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Article

Study on Diamond NV Centers Excited by Green Light Emission from OLEDs

by
Yangyang Guo
1,
Xin Li
1,
Fuwen Shi
2,*,
Wenjun Wang
3 and
Bo Li
1,4,*
1
Key Laboratory of Polar Materials and Devices (MOE), Ministry of Education, Department of Electronics, East China Normal University, Shanghai 200241, China
2
School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
3
School of Physical Science and Information Technology, Liaocheng University, Liaocheng 252059, China
4
Institute of Magnetic Resonance and Molecular Imaging in Medicine, East China Normal University, Shanghai 200241, China
*
Authors to whom correspondence should be addressed.
Photonics 2025, 12(9), 833; https://doi.org/10.3390/photonics12090833
Submission received: 11 July 2025 / Revised: 9 August 2025 / Accepted: 21 August 2025 / Published: 22 August 2025
(This article belongs to the Special Issue Recent Progress in Single-Photon Generation and Detection)
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Abstract

This study demonstrates the feasibility of exciting NV centers using ITO-anode OLED devices, followed by the fabrication of GO/PEDOT:PSS hybrid anodes via spin-coating. Through interfacial modification, the OLED devices exhibit significantly enhanced luminescence intensity, leading to improved NV center excitation efficiency. Experimental results show that the optimized GO/PEDOT:PSS (40%) hybrid anode device achieves a lower turn-on voltage, with the NV center fluorescence peak intensity reaching 3.7 times that of the ITO-anode device, confirming the enhanced excitation effect through interfacial engineering of the light source. By integrating NV centers with OLED technology, this work establishes a new approach for efficient excitation. This integration approach provides a new pathway for applications such as quantum sensing.

1. Introduction

Diamond is an allotrope of carbon, recognized as the hardest natural material. Diamond crystals frequently exhibit lattice defects and impurities. Among these, nitrogen-vacancy (NV) centers are of particular interest. An NV center comprises a nitrogen atom substituting for a carbon atom in the diamond lattice, accompanied by an adjacent vacancy. NV centers can exist in electrically neutral (NV0) or negatively charged (NV−) states, depending on electron trapping during bonding. In this paper, NV refers to the NV− state. NV centers exhibit stable fluorescence emission and long spin coherence times at room temperature, enabling high-fidelity optical readout and precise manipulation of quantum states. Owing to these attributes, NV centers in diamond have emerged as a promising platform for sensing physical quantities such as microwave (MW) fields, magnetic fields, rotation, and temperature [1,2,3,4,5,6,7,8,9,10,11,12,13]. Research on NV center excitation is progressing toward miniaturization, with laser and LED excitation sources being extensively investigated [14,15]. In 2019, a team from Ulm University in Germany pioneered the integration of LEDs into NV center magnetometer systems, establishing the foundation for portable quantum magnetometers [14]. In 2023, researchers at Royal Melbourne Institute of Technology University pioneered an LED–NV center approach in diamond, extending its applications to temperature sensing and demonstrating a high-sensitivity quantum thermometry platform [15]. However, LED excitation systems still require focusing lenses, whereas Organic Light-Emitting Diodes (OLEDs), as planar light sources [16,17,18], can significantly simplify system architecture and better facilitate miniaturization of NV center excitation. Moreover, the inherent flexibility of OLED technology enables its integration with flexible substrates, which may facilitate the development of flexible quantum sensors based on OLED-excited NV centers [19].
OLED is a light-emitting device composed of multiple organic thin films, with its basic structure typically consisting of an anode, cathode, and various functional layers sandwiched in between. The standard configuration from bottom to top includes substrate, anode, hole injection layer (HIL), hole transport layer (HTL), emissive layer (EML), electron transport layer (ETL), electron injection layer (EIL), and cathode. Currently, indium tin oxide (ITO) serves as the primary transparent electrode material for OLEDs due to its excellent optical transparency and electrical conductivity. Nevertheless, its practical applications are limited by several drawbacks, including high cost and substantial interfacial total internal reflection caused by its high refractive index. Alternative materials such as conductive polymers [20,21,22], metal nanowires [23,24,25], graphene [26,27,28], and carbon nanotubes (CNTs) [29,30] have been explored. Among them, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), as an anode material, has attracted considerable attention due to its compatibility with flexible substrates and low production costs. PEDOT:PSS exhibits a relatively high highest occupied molecular orbital (EHOMO) level (−5.1 eV), which reduces the hole injection barrier, along with favorable optical transparency and mechanical flexibility. However, its conductivity is typically below 1 S·cm−1, prompting researchers to develop various modification strategies involving additives such as ethylene glycol [31], salts [32], and acids [33,34,35]. Graphene oxide (GO), a precursor to graphene, possesses a unique two-dimensional structure with abundant surface functional groups (e.g., -OH and -COOH). Its EHOMO (−4.9 eV) and lowest unoccupied molecular orbital (ELUMO) (−1.3 eV) energy levels make it highly suitable for optoelectronic applications [36]. Furthermore, the electronegative nature of GO enables synergistic interactions with PEDOT:PSS, significantly enhancing the performance of composite materials.
In this work, effective optical excitation of NV centers was achieved through integration with OLEDs. The interfacial modification using graphene oxide/poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (GO/PEDOT:PSS) composite anodes was demonstrated to significantly improve the optoelectronic performance of OLED devices, leading to a corresponding enhancement in NV center excitation intensity.

2. Materials and Methods

GO was prepared at 0.5 mg/mL concentration through an optimized Hummer’s approach, with detailed procedures depicted in Figure 1a [37]. The fabrication of hybrid anodes involved two critical steps: spin-coating film formation and acid-modified hybrid anode interface engineering. The PEDOT:PSS solution was first filtered through a 0.45 µm aqueous membrane and then blended with GO at 10%, 40%, and 100% ratios, followed by ultrasonication for 1 h to ensure homogeneous dispersion. Meanwhile, the quartz and ITO substrates were sequentially cleaned with acetone, ethanol, and deionized water (DI), dried at 120 °C for 2 h, and treated with ozone plasma for 15 min. The films were spin-coated using a KV-SC-1550 spin coater (Shenyang Kejing Auto-instrument Co., Ltd., Shenyang, China) at 3000 rpm for 30 s and subsequently annealed on a hotplate at 120 °C for 20 min. For the acid-modified interface engineering, two approaches were employed: the HCl treatment involved immersing the films in 1 M HCl at 160 °C for 30 min, followed by three DI water rinses; alternatively, the H2SO4 treatment consisted of film immersion in 1 M H2SO4, rinsing, and annealing at 160 °C for 1 h. These treatments effectively removed moisture, improved surface morphology, and significantly enhanced charge carrier injection and transport properties. The complete experimental procedure is illustrated in Figure 1b. In the fabrication of OLED devices, molybdenum trioxide (MoO3) was used as the HIL, N,N′-diphenyl-N,N′-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB) as the HTL, tris(8-hydroxyquinolinato) aluminum (Alq3) as the EML, LiF as the EIL, and aluminum (Al) as the cathode. All materials were used without further purification. When the vacuum level was below 5 × 10−4 Pa, MoO3 (1 nm), NPB (40 nm), Alq3 (70 nm), BPhen (10 nm), LiF (0.5 nm), and Al (100 nm) were sequentially evaporated. The energy levels and device structure were shown in Figure 1c. The experiment utilized type Ib diamond substrates (3 mm × 3 mm × 1 mm, (110) plane, nitrogen concentration ~ 100 ppm) prepared by the standard CVD method provided by Yuxin Company, Henan, China. The samples were first subjected to electron beam irradiation with a dose of 1 × 1018 e−/cm2 using an electron irradiation system supplied by Shanghai Gaoying Technology Co., Ltd., Shanghai, China During irradiation, the samples were cooled by a water-cooling system and placed in a chemically stable copper vessel with excellent thermal conductivity. Subsequently, annealing was performed in a tube furnace (SKGL-1200, Shanghai Jujing Precision Instrument Manufacturing Co., Ltd., Shanghai, China) with the sample positioned at the central zone of the furnace tube. The annealing process was conducted at 800 °C for 1 h under a high-purity nitrogen protective atmosphere, ultimately yielding diamond samples with high-density NV centers.
Ultraviolet photoelectron spectroscopy (UPS) measurements of PEDOT:PSS and different volume ratios of GO/PEDOT:PSS hybrid films (10%, 40%, 100%) were conducted using a Scienta R4000 VG Scienta electron spectrometer equipped with a Helium (I) UV source (hν = 21.2 eV) to analyze the energy level changes after interface treatment. The prepared GO/PEDOT:PSS hybrid films and pure PEDOT:PSS films were used as anodes and placed in the evaporation chamber of a multi-source organic molecular thermal evaporation system. The effective emission area of the device was 2 mm × 2 mm. EL performance, including current, brightness, and emission spectra, was measured using a Keithley 2400 source meter (Tektronix, Inc., Beaverton, OR, USA) combined with a PR-655 spectrometer (Photo Research Inc., Chatsworth, CA, USA). All tests were conducted at ambient temperature and pressure. In addition, to construct the NV center sensor, a diamond NV center sample was fixed onto the light-emitting surface of the OLED device using thermal adhesive (Figure 1d). For comparative studies, traditional ITO anode OLED devices were used as reference samples alongside GO/PEDOT:PSS hybrid anode OLED devices. During the testing process, the OLED devices were driven by a DC regulated power supply (WPS3010H) (Shenzhen Mestek Electronic Equipment Technology Co., Ltd., Shenzhen, China), while PL spectra and ODMR signals from the NV center sensors were simultaneously acquired using a custom-built in situ measurement system based on an IHR550 spectrometer (Horiba Scientific, Northampton, UK).

3. Results and Discussion

The prepared OLED devices with different anodes were employed to excite the NV color centers according to the schematic diagram shown in Figure 1d. The PL spectra of NV color centers excited by various anode-based OLED devices and their corresponding operating voltages and currents at identical characteristic peak intensities were systematically investigated, as presented in Figure 2. The inset of Figure 2a clearly demonstrates the characteristic emission peak of diamond NV centers at 637 nm when excited by the ITO-anode OLED device, confirming the feasibility of NV center excitation via OLED technology. However, the characteristic peak intensity achieved with ITO-based OLED devices was relatively weak and lower than that obtained using PEDOT:PSS anode devices. The OLED device incorporating a GO/PEDOT:PSS (40%) hybrid film anode demonstrated significantly enhanced characteristic fluorescence peak intensity from diamond NV centers. Specifically, the emission peak intensity at 637 nm exhibited a 3.2 times increase compared to devices with GO/PEDOT:PSS (10%) hybrid anodes and a 4.6 times enhancement relative to those with GO/PEDOT:PSS (100%) hybrid anodes, substantially surpassing the performance of ITO-based devices. These results indicate that the NV center sensor employing the GO/PEDOT:PSS (40%) hybrid anode achieves optimal fluorescence peak intensity even at a low operating voltage of 14 V, confirming that the interfacial modification of hybrid electrodes effectively enhances NV center excitation efficiency.
The operating voltages required by various OLED devices to achieve comparable characteristic fluorescence peak intensities were systematically measured. As shown in Figure 2b, the ITO-based OLED required an operating voltage of 19.5 V, while the GO/PEDOT:PSS (40%) hybrid anode device achieved equivalent NV center emission intensity at a significantly lower voltage of 14 V. Power consumption analysis demonstrated that the hybrid anode device consumed 88 mW, corresponding to a 22% reduction compared to the 114 mW consumption of the ITO-based reference device. These findings indicate that high-performance OLED devices incorporating GO/PEDOT:PSS (40%) hybrid anodes enable effective excitation of diamond NV centers with substantially reduced operating voltages (28% decrease) and power requirements (22% reduction). The interfacial modification with hybrid anodes relaxes the power supply specifications for OLED-driven NV center applications, thereby enhancing their practical feasibility. Comparative analysis of fluorescence spectra under maximum illumination intensity (Figure 2c) revealed that the hybrid anode device generated the most intense characteristic fluorescence peak, exhibiting a 3.7 times enhancement relative to the ITO-based device. For the statistical validation of experimental results, this study fabricated and tested 20 independent devices for each anode configuration (total sample size N = 100), with all devices evaluated under identical conditions. As shown in Figure 2d, the box-plot analysis of the characteristic NV center emission peak intensity demonstrates consistently high median values across all groups, confirming the excellent reproducibility and statistical robustness of the experimental data.
As shown in Figure 3a, all devices exhibited identical peak wavelengths in their normalized EL spectra, confirming that the selection of anode materials does not affect the recombination zone in OLEDs. The inset of Figure 3a demonstrates that all devices displayed consistent CIE chromaticity coordinates (left panel). These results are in excellent agreement with the normalized EL spectral data presented in Figure 3a. Figure 3b presents a comparative analysis of luminance and maximum brightness for OLEDs with different anodes at an operating voltage of 14 V, with the inset showing the luminance–voltage (L–V) characteristics. Remarkably, the device with a 40% GO/PEDOT:PSS hybrid anode achieved a turn-on voltage of 2.4 V, significantly lower than the turn-on voltages of 4.1 V and 4.3 V observed in devices with PEDOT:PSS and ITO anodes, respectively. Additionally, the device with the GO/PEDOT:PSS (40%) hybrid anode demonstrated a maximum brightness of 36,271 cd/m2, which is 2.37 times greater than the 15,265 cd/m2 achieved by the device with a PEDOT:PSS anode.
In our previous studies [38], the incorporation of GO into PEDOT:PSS leads to the interaction between negatively charged GO sheets and positively charged PEDOT+ chains, causing partial dissociation of PEDOT+ from PSS− chains. Simultaneously, the hydroxyl and carboxyl groups on GO ionize to release H+ ions, which subsequently combine with PSS− to form PSSH. Upon acidic interfacial treatment, the acid provides abundant H+ ions that further react with PSS− in the film to generate neutral PSSH. This process promotes extensive dissociation of PEDOT+ from PSS− chains, while the resulting PSSH can be removed from the film matrix through deionized water washing. After three cycles of deionized water rinsing, the PSS− components in PEDOT:PSS dissolve into water, leaving the PEDOT+ chains retained on the substrate, thereby significantly enhancing the film’s conductivity. The composite film exhibits maximum conductivity (4032 S/cm) at an optimal GO doping ratio of 40%. UPS measurements were conducted to determine the work function (Φ) and highest occupied molecular orbital (EHOMO) energy levels of PEDOT:PSS and GO/PEDOT:PSS composite films with varying volume ratios (10%, 40%, 100%). The performance variations in OLED devices illustrated in Figure 3 elucidate the underlying mechanism responsible for the observed differences in NV center excitation intensity shown in Figure 2. UPS characterization revealed the influence of different anode materials on OLED performance characteristics, with detailed data presented in Table 1. Notably, the GO/PEDOT:PSS (40%) composite exhibited a maximum work function of 5.014 eV, significantly higher than that of pure PEDOT:PSS (4.787 eV). Comparative analysis of energy level differences between composite electrodes and the HIL demonstrated a maximum reduction of 0.556 eV in the energy barrier at the composite electrode/HIL interface when compared to conventional ITO electrodes. This reduced energy barrier facilitates improved energy level alignment and substantially enhances hole injection efficiency. Specifically, the EHOMO level of the GO/PEDOT:PSS (40%) composite anode was measured at 5.256 eV, exceeding that of ITO (4.7 eV). This elevated EHOMO energy effectively minimizes the energy barrier between the anode and the EHOMO level of the HIL (MoO3), thereby optimizing hole injection efficiency and reducing the device turn-on voltage. Consequently, the GO/PEDOT:PSS (40%) composite anode demonstrates significantly enhanced hole injection efficiency due to the synergistic effect of its optimal electrical conductivity (4032 S/cm) and maximum work function (5.014 eV). OLED devices employing this composite anode exhibit superior luminescence intensity compared to those with pure PEDOT:PSS anodes, ultimately achieving more efficient NV center excitation.
A miniaturized nitrogen-vacancy (NV) center quantum sensor based on organic light-emitting diode (OLED) excitation was developed, featuring a compact 22 mm × 14 mm × 7 mm prototype (Figure 4). The integrated design combines an OLED excitation source, NV-doped diamond samples, and a microstrip antenna in a single system. Unlike conventional light-emitting diode (LED) excitation systems [15], the surface-emitting nature of OLEDs eliminates complex optical focusing components, enabling substantial volume reduction while maintaining excitation efficiency. Experimental results in Figure 2 demonstrate significant variations in NV center excitation intensity among different anode materials. Further ODMR spectroscopic characterization (Figure 5) reveals that while anodes produce characteristic resonance peaks from NV centers, substantial differences exist in signal quality. Specifically, the ITO anode yields an ODMR spectrum with merely an 18 signal-to-noise ratio (SNR) (Figure 5a), whereas the GO/PEDOT:PSS (40%) hybrid anode achieves a twofold enhancement with 41 SNR (Figure 5b). The ODMR CR achieved with the ITO anode was measured to be 1.7% (Figure 5a), whereas the GO/PEDOT:PSS (40%) composite anode demonstrated a significant enhancement, reaching 3% (Figure 5b). This performance improvement primarily stems from the superior excitation brightness characteristics of the hybrid anode. Through optimized energy-level structure design, this anode not only effectively enhances the fluorescence emission intensity of NV centers but, more importantly, significantly improves ODMR signal quality. Notably, the current OLED excitation intensity remains below the spin polarization saturation threshold of NV centers. Within this operational regime, increasing the excitation power can further improve the spin polarization rate, thereby effectively enhancing the modulation depth (CR) of ODMR spectra [39,40]. These findings establish the GO/PEDOT:PSS (40%) hybrid anode as a promising material platform for advancing NV center-based quantum sensitivity, providing crucial material foundations for developing high-performance solid-state quantum sensors. Experimental results demonstrate that the proposed design maintains sensing performance while achieving significant volume reduction compared to conventional LED-based systems. Notably, the inherent flexibility of OLED technology offers promising potential for NV center sensor applications in wearable devices and other emerging fields. This study provides an innovative solution for advancing the practical development of quantum sensors.

4. Conclusions

This study demonstrates the feasibility of NV center excitation using OLED devices. Through acid-modified interfacial engineering of the OLED anode, a significant enhancement in NV center excitation efficiency was achieved. Experimental results show that the GO/PEDOT:PSS (40%) composite anode exhibits outstanding performance, with a conductivity of 4032 S/cm and a work function of 5.014 eV. Compared to conventional ITO-based devices, this novel anode architecture yields a 3.7-fold increase in NV center fluorescence peak intensity, conclusively demonstrating the performance-enhancing effect of the acid-modified interfacial engineering. By integrating NV centers with OLED technology, we have developed a novel approach for efficient green-light excitation. Furthermore, we have successfully implemented a miniaturized NV center sensor based on OLED excitation while demonstrating controllable spin-state manipulation. This OLED-based miniaturization technology enables potential applications in quantum sensing, facilitating the practical advancement of quantum technologies.

Author Contributions

Conceptualization, B.L. and Y.G.; methodology, Y.G., X.L. and W.W.; formal analysis, F.S. and B.L. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the National Key Research and Development Program of China (Grand No. 2024YFB4611400).

Institutional Review Board Statement

Not applicable.

Data Availability Statement

All of the data reported in the paper are presented in the main text. Other data will be provided on request.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Carmiggelt, J.J.; Bertelli, I.; Mulder, R.W.; Teepe, A.; Elyasi, M.; Simon, B.G.; Bauer, G.E.W.; Blanter, Y.M.; Sar, T.V.D. Broadband microwave detection using electron spins in a hybrid diamond-magnet sensor chip. Nat. Commun. 2023, 14, 490. [Google Scholar] [CrossRef] [PubMed]
  2. Thiel, L.; Rohner, D.; Ganzhorn, M.; Appel, P.; Neu, E.; Müller, B.; Kleiner, R.; Koelle, D.; Maletinsky, P. Quantitative nanoscale vortex imaging using a cryogenic quantum magnetometer. Nat. Nanotechnol. 2016, 11, 677–681. [Google Scholar] [CrossRef] [PubMed]
  3. Clevenson, H.; Trusheim, M.E.; Teale, C.; Schröder, T.; Braje, D.; Englund, D. Broadband magnetometry and temperature sensing with a light-trapping diamond waveguide. Nat. Phys. 2015, 11, 393–397. [Google Scholar] [CrossRef]
  4. Wang, J.; Feng, F.; Zhang, J.; Chen, J.; Zheng, Z.; Guo, L.; Zhang, W.; Song, X.; Guo, G.; Fan, L.; et al. High-sensitivity temperature sensing using an implanted single nitrogen-vacancy center array in diamond. Phys. Rev. B 2015, 91, 155404. [Google Scholar] [CrossRef]
  5. Neumann, P.; Jakobi, I.; Dolde, F.; Burk, C.; Reuter, R.; Waldher, G.; Honert, J.; Wolf, T.; Brunner, A.; Wrachtrup, J. High-precision nanoscale temperature sensing using single defects in diamond. Nano Lett. 2013, 13, 2738–2742. [Google Scholar] [CrossRef]
  6. Jarmola, A.; Lourette, S.; Acosta, V.M.; Birdwell, A.G.; Blümler, P.; Budker, D.; Ivanov, T.; Malinovsky, V.S. Demonstration of diamond nuclear spin gyroscope. Sci. Adv. 2021, 7, eabl3840. [Google Scholar] [CrossRef]
  7. Wood, A.A.; Lilette, E.; Fein, Y.Y.; Tomek, N.; McGuinness, L.P.; Hollenberg, L.C.; Scholten, R.E.; Marti, A.M. Quantum measurement of a rapidly rotating spin qubit in diamond. Sci. Adv. 2018, 4, eaar7691. [Google Scholar] [CrossRef]
  8. Schoenfeld, R.S.; Harneit, W. Real time magnetic field sensing and imaging using a single spin in diamond. Phys. Rev. Lett. 2011, 106, 030802. [Google Scholar] [CrossRef]
  9. Wood, A.A.; Aeppli, A.G.; Lilette, E.; Fein, Y.Y.; Stacey, A.; Hollenberg, L.C.L.; Scholten, R.E.; Martin, A.M. T2-limited sensing of static magnetic fields via fast rotation of quantum spins. Phys. Rev. B 2018, 98, 174114. [Google Scholar] [CrossRef]
  10. Wang, Z.; Kong, F.; Zhao, P.; Huang, Z.; Yu, P.; Wang, Y.; Shi, F.; Du, J. Picotesla magnetometry of microwave fields with diamond sensors. Sci. Adv. 2022, 8, eabq8158. [Google Scholar] [CrossRef]
  11. Mariani, G.; Nomoto, S.; Kashiwaya, S.; Nomura, S. System for the remote control and imaging of MW fields for spin manipulation in NV centers in diamond. Sci. Rep. 2020, 10, 4813. [Google Scholar] [CrossRef]
  12. Casola, F.; Van Der Sar, T.; Yacoby, A. Probing condensed matter physics with magnetometry based on nitrogen-vacancy centres in diamond. Nat. Rev. Mater. 2018, 3, 17088. [Google Scholar] [CrossRef]
  13. Savage, N. Quantum diamond sensors. Nature 2021, 591, S37. [Google Scholar] [CrossRef]
  14. Sturner, F.M.; Brenneis, A.; Kassel, J.; Wostradowski, U.; Rölve, R.; Fuchs, T.; Nakamura, K.; Sumiya, H.; Onoda, S.; Isoya, J.; et al. Compact integrated magnetometer based on nitrogen-vacancy centres in diamond. Diam. Relat. Mater. 2019, 93, 59–65. [Google Scholar] [CrossRef]
  15. Abrahams, G.J.; Ellul, E.; Robertson, I.S.; Khalid, A.; Greentree, A.D.; Gibson, B.C.; Tetienne, J.P. Handheld device for naocontact thermometry via optically detected magnetic resonance of proximate diamond sensors. Phys. Rev. Appl. 2023, 19, 054076. [Google Scholar] [CrossRef]
  16. Fo, W.Z.; Li, J.; Lei, Y.X.; Wei, B.; Zhang, Z.L. A facile and efficient preparation method for the doped light emitting layer in OLEDs: Blade-coated planar source evaporation. Org. Electron. 2024, 124, 106961. [Google Scholar] [CrossRef]
  17. Bai, G.L.; Yang, J.J.; Wu, S.X.; Ma, X.X.; Ma, Y.L.; Zhou, L.; Li, C.B.; Shen, S. Theoretical analysis and design for highly collimated planar light source based on organic light-emitting diodes using Fresnel lens. Appl. Phys. Express 2018, 11, 072101. [Google Scholar] [CrossRef]
  18. Käläntär, K. Optical performance characterization of curved OLED light sources. J. Soc. Inf. Disp. 2021, 29, 105–114. [Google Scholar] [CrossRef]
  19. Lee, S.M.; Kwon, J.H.; Kwon, S.; Choi, K.C. A review of flexible OLEDs toward highly durable unusual displays. IEEE Trans. Electron Devices 2017, 64, 1922–1931. [Google Scholar] [CrossRef]
  20. Wu, X.; Fu, W.; Chen, H. Conductive polymers for flexible and stretchable organic optoelectronic applications. ACS Appl. Polym. Mater. 2022, 4, 4609–4623. [Google Scholar] [CrossRef]
  21. Wang, Y.; Liu, S.; Dang, F.; Li, Y.; Yin, Y.; Liu, J.; Xu, K.; Piao, X.; Xie, W.F. An efficient flexible white organic light-emitting device with a screen-printed conducting polymer anode. J. Phys. D Appl. Phys. 2012, 45, 402002. [Google Scholar] [CrossRef]
  22. Ummartyotin, S.; Juntaro, J.; Wu, C.; Sain, M.; Manuspiya, H. Deposition of PEDOT:PSS nanoparticles as a conductive microlayer anode in OLEDs device by desktop inkjet printer. J. Nanomater. 2011, 2011, 606714. [Google Scholar] [CrossRef]
  23. Liu, P.; Wang, J.; Cheng, J.; Liu, L.; Wang, H.; Zeng, B.; Chi, F. A new structure of flexible OLED with copper nanowire anode and graphere oxide/PEDOT:PSS anode buffer layer. Surf. Rev. Lett. 2020, 27, 1950171. [Google Scholar] [CrossRef]
  24. Kang, H.; Kim, J.S.; Choi, S.R.; Kim, Y.H.; Kim, D.H.; Kim, J.G.; Lee, T.W.; Cho, J.H. Electroplated core–shell nanowire network electrodes for highly efficient organic light-emitting diodes. Nano Converg. 2022, 9, 1. [Google Scholar] [CrossRef] [PubMed]
  25. Lee, J.; An, K.; Won, P.; Ka, Y.; Hwang, H.; Moon, H.; Kwon, Y.; Hong, S.; Kim, C.; Lee, C.; et al. A dual-scale metal nanowire network transparent conductor for highly efficient and flexible organic light emitting diodes. Nanoscale 2017, 9, 1978–1985. [Google Scholar] [CrossRef]
  26. Ma, L.P.; Wu, Z.; Yan, Y.; Zhang, D.; Dong, S.; Du, J.; Ma, D.; Cheng, H.M.; Ren, W. Stably doped graphene transparent electrode with improved light-extraction for efficient flexible organic light-emitting diodes. Nano Res. 2023, 16, 12788–12793. [Google Scholar] [CrossRef]
  27. Weng, Z.; Dixon, S.C.; Lee, L.Y.; Humphreys, C.J.; Guiney, I.; Fenwick, O.; Gillin, W.P. Wafer-Scale Graphene Anodes Replace Indium Tin Oxide in Organic Light-Emitting Diodes. Adv. Opt. Mater. 2022, 10, 2101675. [Google Scholar] [CrossRef]
  28. Wang, T.; Jing, L.C.; Bao, Z.; Qian, P.; Geng, W.; Ethiraj, A.S.; Geng, W.H.; Chen, L.; Zhu, Q.; Geng, H.Z. Strong adhesion and high optoelectronic performance hybrid graphene/carbon nanotubes transparent conductive films for green-light OLED devices. Surf. Interfaces 2021, 24, 101137. [Google Scholar] [CrossRef]
  29. Tian, Y.; Wang, T.; Zhu, Q.; Zhang, X.; Ethiraj, A.S.; Geng, W.M.; Geng, H.Z. High-performance transparent PEDOT:PSS/CNT films for OLEDs. Nanomaterials 2021, 11, 2067. [Google Scholar] [CrossRef]
  30. Wang, T.; Jing, L.C.; Zhu, Q.; Ethiraj, A.S.; Tian, Y.; Zhao, H.; Yuan, X.T.; Wen, J.G.; Li, L.K.; Geng, H.Z. Fabrication of architectural structured polydopamine-functionalized reduced graphene oxide/carbon nanotube/PEDOT:PSS nanocomposites as flexible transparent electrodes for OLEDs. Appl. Surf. Sci. 2020, 500, 143997. [Google Scholar] [CrossRef]
  31. Kim, G.H.; Shao, L.; Zhang, K.; Ripe, K.P. Engineered doping of organic semiconductors for enhanced thermoelectric efficiency. Nat. Mater. 2013, 12, 719–723. [Google Scholar] [CrossRef] [PubMed]
  32. Xia, Y.; Ouyang, J. Salt-induced charge screening and significant conductivity enhancement of conducting poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate). Macromolecules 2009, 42, 4141–4147. [Google Scholar] [CrossRef]
  33. Xia, Y.; Ouyang, J. Significant conductivity enhancement of conductive poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate) films through a treatment with organic carboxylic acids and inorganic acids. ACS Appl. Mater. Interfaces 2010, 2, 474–483. [Google Scholar] [CrossRef] [PubMed]
  34. Cruz-Cruz, I.; Reyes-Reyes, M.; López-Sandoval, R. Formation of polystyrene sulfonic acid surface structures on poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate) thin films and the enhancement of its conductivity by using sulfuric acid. Thin Solid Film. 2013, 531, 385–390. [Google Scholar] [CrossRef]
  35. Zhao, Z.; Liu, Q.; Zhang, W.; Yang, S. Conductivity enhancement of PEDOT:PSS film via sulfonic acid modification: Application as transparent electrode for ITO-free polymer solar cells. Sci. China Chem. 2018, 61, 1179–1186. [Google Scholar] [CrossRef]
  36. Lee, B.R.; Kim, J.; Kang, D.; Lee, D.W.; Ko, S.J.; Lee, H.J.; Lee, C.L.; Kim, J.Y.; Shin, H.S.; Song, M.H. Highly efficient polymer light-emitting diodes using graphene oxide as a hole transport layer. ACS Nano 2012, 6, 2984–2991. [Google Scholar] [CrossRef]
  37. Yu, H.; Zhang, B.; Bulin, C.; Li, R.H.; Xing, R.G. High-efficient synthesis of graphene oxide based on improved hummers method. Sci. Rep. 2016, 6, 36143. [Google Scholar] [CrossRef]
  38. Guo, Y.Y.; Li, X.; Li, B.; Wang, W.J. Hybrid electrode interface modification enhances OLEDs performance. Opt. Mater. Express 2024, 14, 972–982. [Google Scholar] [CrossRef]
  39. Feng, Y.Y.; Li, Z.H.; Zhang, Y.; Cui, L.X.; Guo, Q.; Guo, H.; Wen, H.F.; Liu, W.Y.; Tang, J.; Liu, J. Optimization of optical control of nitrogen vacancy centers in solid diamond. Acta Phys. Sin. 2020, 69, 147601. [Google Scholar] [CrossRef]
  40. Barry, J.F.; Schloss, J.M.; Bauch, E.; Turner, M.J.; Hart, C.A.; Pham, L.M.; Walsworth, R.L. Sensitivity optimization for NV-diamond magnetometry. Rev. Mod. Phys. 2020, 92, 015004. [Google Scholar] [CrossRef]
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Figure 1. (a) Schematic illustration of the GO synthesis procedure. (b) Experimental flowchart for the preparation and interfacial treatment of GO/PEDOT:PSS hybrid films. (c) Energy level diagram and device architecture of the OLEDs. (d) Structural schematics of NV color centers excited by OLED devices.
Figure 1. (a) Schematic illustration of the GO synthesis procedure. (b) Experimental flowchart for the preparation and interfacial treatment of GO/PEDOT:PSS hybrid films. (c) Energy level diagram and device architecture of the OLEDs. (d) Structural schematics of NV color centers excited by OLED devices.
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Figure 2. (a) Fluorescence spectra of NV centers under excitation by OLED devices with ITO anode, PEDOT:PSS anode, and hybrid anode (Vworking voltage = 14 V). (b) Working voltage and current required to achieve equivalent NV center fluorescence intensity under excitation (c) Fluorescence spectra of NV centers under maximum emission intensity from OLED devices with ITO anode, PEDOT:PSS anode, and hybrid anode. (d) Box plot of characteristic peak intensities of NV centers excited by OLED devices with ITO anode, PEDOT:PSS anode, and hybrid anode at maximum emission intensity (N = 100).
Figure 2. (a) Fluorescence spectra of NV centers under excitation by OLED devices with ITO anode, PEDOT:PSS anode, and hybrid anode (Vworking voltage = 14 V). (b) Working voltage and current required to achieve equivalent NV center fluorescence intensity under excitation (c) Fluorescence spectra of NV centers under maximum emission intensity from OLED devices with ITO anode, PEDOT:PSS anode, and hybrid anode. (d) Box plot of characteristic peak intensities of NV centers excited by OLED devices with ITO anode, PEDOT:PSS anode, and hybrid anode at maximum emission intensity (N = 100).
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Figure 3. (a) Normalized EL spectra of OLED devices with different anode configurations (main panel). Insets display: left—corresponding CIE 1931 chromaticity coordinates; right—photographic images of the 40% hybrid anode. (b) Comparative analysis of luminance characteristics and maximum brightness for OLED devices employing various anodes at an operating voltage of 14 V (main panel), with the inset illustrating the luminance–voltage (L–V) characteristics.
Figure 3. (a) Normalized EL spectra of OLED devices with different anode configurations (main panel). Insets display: left—corresponding CIE 1931 chromaticity coordinates; right—photographic images of the 40% hybrid anode. (b) Comparative analysis of luminance characteristics and maximum brightness for OLED devices employing various anodes at an operating voltage of 14 V (main panel), with the inset illustrating the luminance–voltage (L–V) characteristics.
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Figure 4. (a) Microstrip antenna design for miniaturized OLED-excited NV–center sensor. (b) Integrated quantum sensing device based on miniaturized OLED-excited NV centers.
Figure 4. (a) Microstrip antenna design for miniaturized OLED-excited NV–center sensor. (b) Integrated quantum sensing device based on miniaturized OLED-excited NV centers.
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Figure 5. ODMR spectra of NV centers based on (a) ITO anode, (b) 40% hybrid anode, and (c) 100% hybrid anode, along with (d) the corresponding SNR and CR comparison of ODMR signals for different anodes.
Figure 5. ODMR spectra of NV centers based on (a) ITO anode, (b) 40% hybrid anode, and (c) 100% hybrid anode, along with (d) the corresponding SNR and CR comparison of ODMR signals for different anodes.
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Table 1. Ecutoff, Φ, EHOMO of PEDOT:PSS, and different volume ratio of GO/PEDOT:PSS hybrid films with interface treatment (10%, 40%, 100%) measured from UPS spectra.
Table 1. Ecutoff, Φ, EHOMO of PEDOT:PSS, and different volume ratio of GO/PEDOT:PSS hybrid films with interface treatment (10%, 40%, 100%) measured from UPS spectra.
AnodeEcutoff (eV)Φ (eV)EHOMO edge − EF (eV)EHOMO (eV)
PEDOT:PSS16.4134.7870.2465.033
10%16.2504.9500.2175.167
40%16.1865.0140.2425.256
100%16.2154.9850.2265.211
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Guo, Y.; Li, X.; Shi, F.; Wang, W.; Li, B. Study on Diamond NV Centers Excited by Green Light Emission from OLEDs. Photonics 2025, 12, 833. https://doi.org/10.3390/photonics12090833

AMA Style

Guo Y, Li X, Shi F, Wang W, Li B. Study on Diamond NV Centers Excited by Green Light Emission from OLEDs. Photonics. 2025; 12(9):833. https://doi.org/10.3390/photonics12090833

Chicago/Turabian Style

Guo, Yangyang, Xin Li, Fuwen Shi, Wenjun Wang, and Bo Li. 2025. "Study on Diamond NV Centers Excited by Green Light Emission from OLEDs" Photonics 12, no. 9: 833. https://doi.org/10.3390/photonics12090833

APA Style

Guo, Y., Li, X., Shi, F., Wang, W., & Li, B. (2025). Study on Diamond NV Centers Excited by Green Light Emission from OLEDs. Photonics, 12(9), 833. https://doi.org/10.3390/photonics12090833

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