We report the characterization of back-gated field-effect transistors fabricated using platinum diselenide (PtSe2) ultrathin films as a channel. We perform a detailed study of the electrical conduction as well as of the photoconductivity. From the ga...
We reported the photoconduction properties of tungsten disulfide (WS2) nanoflakes obtained by the mechanical exfoliation method. The photocurrent measurements were carried out using a 532 nm laser source with different illumination powers. The result...
In the last two decades, variably doped strontium barium niobate (SBN) has attracted a lot of scientific interest mainly due to its specific non-linear optical response. Comparably, the parental compound, i.e., undoped SBN, appears to be less studied...
A fractional description for the optically induced mechanisms responsible for conductivity and multiphotonic effects in ZnO nanomaterials is studied here. Photoconductive, electrical, and nonlinear optical phenomena exhibited by pure micro and nanost...
A decrease in conductivity under illumination, known as negative photoconductivity, has been observed in various semiconductors and is commonly attributed to trapping of excess carriers by deep centers. Here, we demonstrate that negative photoconduct...
Vacuum ultraviolet radiation (VUV, from 100 nm to 200 nm wavelength) is indispensable in many applications, but its detection is still challenging. We report the development of a VUV photoconductive detector, based on titanium dioxide (TiO2) nanopart...
Hybrid organic–inorganic perovskites, while well examined for photovoltaic applications, remain almost completely unexplored in the terahertz (THz) range. These low-cost hybrid materials are extremely attractive for THz applications because the...
Rock varnishes, complex structures formed by long-term deposition on rocks, exhibit unique light absorption characteristics and are widely distributed across arid environments on Earth’s surface. The varnishes possess the ability to absorb and...
In this study, the efficient generation of terahertz radiation by a dipole photoconductive antenna, based on a thin island film of a topological insulator, was experimentally demonstrated. The performance of the Bi1.9Sb0.1Te2Se antenna was shown to b...
The main goal of this work is to provide a general description of the negative photoconductivity effect observed in Ag/AgO films grown by the spray-pyrolysis technique. X-ray diffractograms display hybrid films with high texturized AgO and metallic A...
In this work, colloidal perovskite nanocrystals (PNCs) are used to sensitize the photoconductivity of nanocrystalline ZnO films in the visible range. Nanocrystalline ZnO with a crystallite size of 12–16 nm was synthesized by precipitation of a...
The efficiency of the generation of terahertz radiation from nitrogen-doped (∼
The quantum efficiency
This paper presents an integrated germanium (Ge)-based THz impulse radiator with an optical waveguide coupled photoconductive switch in a low-cost silicon-on-insulator (SOI) process. This process provides a Ge thin film, which is used as photoconduct...
Current photoconductive antennas (PCAs) fail to maximize the use of photogenerated carriers at the electrode edges. To address this limitation, we designed a novel PCA structure featuring a ring electrode and a disc electrode. The positive and negati...
Surface plasmon technology is regarded as having significant potential for the enhancement of the performance of 2D oxide semiconductors, especially in terms of improving the light absorption of 2D MoO3 photodetectors. An ultrathin MoO3/Ir/SiO2/Si he...
Cu (II) protoporphyrin Cu-PP-IX and chlorin Cu-C-e6 were found to have both thin solid film formation and charge carrier transport abilities. In the layers deposited by resistive thermal evaporation, the mobilities of holes and electrons are on the o...
Terahertz noise sources have important application prospects in noise figure measurements. In this paper, a 0.4 THz broadband terahertz noise source based on a photoconductive antenna is proposed. As a demonstration of feasibility, this terahertz noi...
As core components of terahertz (THz) radiation sources, photoconductive antennas (PCAs) suffer from performance limitations due to inefficient carrier generation/transport and space-charge shielding effects. This study first introduced cylindrical A...
The novel design of a terahertz large aperture photoconductive antenna (LAPCA) is reported. It features a longitudinal orientation of the bias electric field within the photoconductive substrate, and has the advantage of a small interelectrode gap, r...
Titanium dioxide nanoparticles were synthesized via hydrothermal treatment of tetrabutyl titanate in sulfuric acid, with controlled reaction times (10 h and 24 h) and zinc sulfate as a modifier. XRD confirmed exclusive formation of the anatase phase,...
A photoconductive logarithmic spiral antenna with saw-toothed plasmonic contact electrodes is proposed to provide a higher terahertz radiation compared with the conventional photoconductive antenna (PCA). The use of saw-toothed plasmonic contact elec...
Two-dimensional materials represented by graphene have attracted extensive interest owing to the unique layer-dependent physical properties that are tunable with various external fields. In addition, by stacking two or more 2D materials together, a n...
Photoconductive semiconductor switching (PCSS) devices have unique characteristics to address the growing need for electrically isolated, optically gated, picosecond-scale jitter devices capable of operating at high voltage, current, and frequency. T...
We investigate the photoconductivity properties of lead sulphide (PbS) quantum dot ensembles in lithographically tailored gold electrodes with smallest gaps of 15 nm. We demonstrate that quantum dots are reliable nanoscale light/current converters an...
The terahertz wave generation by spiral photoconductive antennas fabricated on low-temperature In0.5Ga0.5As films and In0.5Ga0.5As/In0.5Al0.5As superlattices is studied by the terahertz time-domain spectroscopy method. The structures were obtained by...
We investigated the optoelectronic properties of lead sulphide (PbS) quantum dot films in lithographically tailored gold nanogap electrodes. In particular, we aimed at the correlated measurement of photoconductivity and luminescence as a tool to char...
A simple and effective technique to characterize the photoconductivity (PC) of lithium niobate is presented. The technique is based on the modulation of the external field and on the observation of the optical response of the material as a function o...
The model of multiple trapping into energy-distributed states is a successful tool to describe the transport of nonequilibrium charge carriers in amorphous semiconductors. Under certain conditions, the model leads to anomalous diffusion equations tha...
Electron dynamics in the polycrystalline bismuth films were investigated by measuring emitted terahertz (THz) radiation pulses after their photoexcitation by tunable wavelength femtosecond duration optical pulses. Bi films were grown on metallic Au,...
The optoelectronic properties of a new poly(2-ethyl-3-methylindole) (MPIn) are discussed in this paper. The absorption and photoluminescence spectra were studied. The electronic spectrum of MPIn showed a single absorption maximum at 269 nm that is ch...
The photoinduced microwave complex permittivity of a highly resistive single-crystal silicon wafer was extracted from a bistatic free-space characterization test bench operating in the 26.5–40 GHz frequency band under CW optical illumination at wavel...
The photocurrent in tellurium nanowire (Te NW) exhibits a subtle influence by many extrinsic factors. Herein, we fabricate Te NW devices and explore their photoresponse properties in detail. It is observed that the current increases greatly at low en...
In this work, plasmonic photoconductive antenna (PCA) structures with different grating-width and gap configurations were numerically investigated to evaluate their influence on transient-current generation and terahertz (THz) emission performance. T...
In this paper, a three-layer GaAs photoconductive semiconductor switch (GaAs PCSS) is designed to withstand high voltage from 20 to 35 kV. The maximum avalanche gain and minimum on-state resistance of GaAs PCSS are 1385 and 0.58 Ω, respectively, whic...
A diffractive grating is a well-known optical component and is extensively used in many applications. This research work explores application of the diffractive grating in a photoconductive antenna (PCA) of a terahertz time domain spectroscopy (THz-T...
Conventional multi-electrode photoconductive antennas (PCAs) can only radiate linearly polarized terahertz waves with polarization angles in increments of 45°, limiting their use for the characterization of diverse anisotropic material. We propos...
In this paper, the positive and negative symmetric pulses with a fast rising edge were generated by a GaAs photoconductive semiconductor switch (PCSS). When the GaAs PCSS was biased at 2.0 kV and triggered by a femtosecond laser pulse with a pulse en...
Since the definitions of the two-dimensional (2D) optical absorption coefficient and photoconductivity are independent of the thickness of 2D materials, they are more suitable than the dielectric function to describe the optical properties of 2D mate...
The current need to accelerate the adoption of photovoltaic (PV) systems has increased the need to explore new nanomaterials that can harvest and convert solar energy into electricity. Transition metal dichalcogenides (TMDCs) are good candidates beca...
Persistent photoconductivity (PPC) spectra of HgTe/CdHgTe heterostructures with double quantum wells with different cap layers have been studied in the radiation excitation range 0.62–3.1 eV. We have shown that the material of the cap layer def...
Nanoscale structure has a large effect on the optoelectronic properties of InGaN, a material vital for energy saving technologies such as light emitting diodes. Photoconductive atomic force microscopy (PC-AFM) provides a new way to investigate this e...
We have developed a real time ultraviolet (UV) imaging system that can visualize both invisible UV light and a visible (VIS) background scene in an outdoor environment. As a UV/VIS image sensor, an organic photoconductive film (OPF) imager is employe...
To investigate the effects of the pixel sizes and the electrode structures on the performance of Ge-based terahertz (THz) photoconductive detectors, vertical structure Ge:Ga detectors with different structure parameters were fabricated. The character...
Negative photoconductivity (NPC) in low-dimensional materials has attracted considerable interest for its potential in novel optoelectronic devices. Here, we report an ultra-broadband NPC response in FePd2Te2, a van der Waals ferromagnet, spanning fr...
Bi2O2Se, as a novel two-dimensional semiconductor material, has been prepared and used in the field of photodetection. Herein, Bi2O2Se nanosheets were prepared using a hydrothermal method. Bi2O2Se films were also prepared using a drop-coating method....
The GaN photoconductive semiconductor switches (PCSSs) with low leakage current and large on-state current are suitable for several applications, including fast switching and high-power electromagnetic pulse equipment. This paper demonstrates a high-...
It has been shown recently that a photoconductive antenna (PCA) based on a nitrogen-doped diamond can be effectively excited by the second harmonic of a Ti:sapphire laser (λ = 400 nm). The THz emission performance of the PCA can be significant...
Platinum (Pt) is a rare and precious metal element with numerous unique properties. These properties have led to the widespread use of Pt in electronic components, thermocouples, and high-temperature devices. In this study, we present the bolometric...
A low-complexity Hall-based measurement system implementing a dark/illuminated differential estimator of the majority-carrier photoconductive response is assessed on n-type crystalline silicon wafers with contrasting doping concentrations. The setup...
of 7