Open AccessThis article is
- freely available
Organic Plasmon-Emitting Diodes for Detecting Refractive Index Variation
Institute of Electro-Optical Science and Technology, National Taiwan Normal University, No. 88, Sec. 4, Ting-Chou Road, Taipei 11677, Taiwan
* Author to whom correspondence should be addressed.
Received: 8 April 2013; in revised form: 17 June 2013 / Accepted: 24 June 2013 / Published: 28 June 2013
Abstract: A photo-excited organic layer on a metal thin film with a corrugated substrate was used to generate surface plasmon grating coupled emissions (SPGCEs). Directional emissions corresponded to the resonant condition of surface plasmon modes on the Au/air interface. In experimental comparisons of the effects of different pitch sizes on the plasmonic band-gap, the obtained SPGCEs were highly directional, with intensity increases as large as 10.38-fold. The FWHM emission spectrum was less than 70 nm. This method is easily applicable to detecting refractive index changes by using SP-coupled fluorophores in which wavelength emissions vary by viewing angle. The measurements and calculations in this study confirmed that the color wavelength of the SPGCE changed from 545.3 nm to 615.4 nm at certain viewing angles, while the concentration of contacting glucose increased from 10 to 40 wt%, which corresponded to a refractive index increase from 1.3484 to 1.3968. The organic plasmon-emitting diode exhibits a wider linearity range and a resolution of the experimental is 1.056 × 10−3 RIU. The sensitivity of the detection limit for naked eye of the experimental is 0.6 wt%. At a certain viewing angle, a large spectral shift is clearly distinguishable by the naked eye unaided by optoelectronic devices. These experimental results confirm the potential applications of the organic plasmon-emitting diodes in a low-cost, integrated, and disposable refractive-index sensor.
Keywords: surface plasmon grating coupled emission (SPGCE); directional; plasmonic band-gap; refractive-index sensor
Citations to this Article
Cite This Article
MDPI and ACS Style
Chiu, N.-F.; Cheng, C.-J.; Huang, T.-Y. Organic Plasmon-Emitting Diodes for Detecting Refractive Index Variation. Sensors 2013, 13, 8340-8351.
Chiu N-F, Cheng C-J, Huang T-Y. Organic Plasmon-Emitting Diodes for Detecting Refractive Index Variation. Sensors. 2013; 13(7):8340-8351.
Chiu, Nan-Fu; Cheng, Chih-Jen; Huang, Teng-Yi. 2013. "Organic Plasmon-Emitting Diodes for Detecting Refractive Index Variation." Sensors 13, no. 7: 8340-8351.