Bao Guanghong, Li Dabing, Sun Xiaojuan, Jiang Mingming, Li Zhiming, Song Hang, Jiang Hong, Chen Yiren, Miao Guoqing, Zhang Zhiwei
Opt Express. 2014 Oct 6;22(20):24286-93. doi: 10.1364/OE.22.024286.
An enhanced spectral response was realized in an AlGaN-based solar-blind ultraviolet (SB-UV) detector using aluminum (Al) nanoparticles (NPs) of 20-60 nm. The peak responsivity of the detector (about 288 nm) with 60 nm Al NPs is more than two times greater than that of a detector without Al NPs under a 5-V bias, reaching 0.288 A/W. To confirm the enhancement mechanism of the Al NPs, extinction spectra were simulated using time-domain and frequency-domain finite-element methods. The calculation results show that the dipole surface plasmon resonance wavelength of the Al NPs is localized near the peak responsivity position of AlGaN-based SB-UV detectors. Thus, the improvement in the detectors can be ascribed to the localized surface plasmon resonance effect of the Al NPs. The localized electric field enhancement and related scattering effect result in the generation of more electron-hole pairs and thus a higher responsivity. In addition, the dark current of AlGaN-based SB-UV detectors does not increase after the deposition of Al nanoparticles. The results presented here is promising for applications of AlGaN-based SB-UV detectors.
在一种基于AlGaN的日盲紫外（SB-UV）探测器中，通过使用20 - 60 nm的铝（Al）纳米颗粒（NPs）实现了增强的光谱响应。在5 V偏压下，具有60 nm Al NPs的探测器（约288 nm）的峰值响应度比没有Al NPs的探测器高出两倍多，达到0.288 A/W。为了确定Al NPs的增强机制，使用时域和频域有限元方法模拟了消光光谱。计算结果表明，Al NPs的偶极表面等离子体共振波长位于基于AlGaN的SB-UV探测器的峰值响应度位置附近。因此，探测器的性能提升可归因于Al NPs的局域表面等离子体共振效应。局域电场增强和相关散射效应导致产生更多的电子 - 空穴对，从而具有更高的响应度。此外，在沉积Al纳米颗粒后，基于AlGaN的SB-UV探测器的暗电流并未增加。这里展示的结果对于基于AlGaN的SB-UV探测器的应用具有前景。
