Kaushik Shuchi, Karmakar Subhajit, Bisht Prashant, Liao Che-Hao, Li Xiaohang, Varshney Ravendra Kumar, Mehta Bodh Raj, Singh Rajendra
Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
Advanced Semiconductor Laboratory, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Nanotechnology. 2022 Jan 12;33(14). doi: 10.1088/1361-6528/ac4285.
The appealing properties of tunable direct wide bandgap, high-temperature robustness and chemical hardness, make AlGaN a promising candidate for fabricating robust solar-blind photodetectors (PDs). In this work, we have utilized the optical phenomenon of localized surface plasmon resonance (LSPR) in metal nanoparticles (NPs) to significantly enhance the performance of solar-blind AlGaN metal-semiconductor-metal PDs that exhibit high-temperature robustness. We demonstrate that the presence of palladium (Pd) NPs leads to a remarkable enhancement by nearly 600, 300, and 462%, respectively, in the photo-to-dark current ratio (PDCR), responsivity, and specific detectivity of the AlGaN PD at the wavelength of 280 nm. Using the optical power density of only 32W cmat -10 V, maximum values of ∼3 × 10, 2.7 AW, and 2.4 × 10Jones are found for the PDCR, responsivity and specific detectivity, respectively. The experimental observations are supported by finite difference time domain simulations, which clearly indicate the presence of LSPR in Pd NPs decorated on the surface of AlGaN. The mechanism behind the enhancement is investigated in detail, and is ascribed to the LSPR induced effects, namely, improved optical absorption, enhanced local electric field and LSPR sensitization effect. Moreover, the PD exhibits a stable operation up to 400 K, thereby exhibiting the high-temperature robustness desirable for commercial applications.
可调谐直接宽带隙、高温稳定性和化学硬度等吸引人的特性，使氮化铝镓成为制造坚固耐用的日盲光电探测器（PD）的有前途的候选材料。在这项工作中，我们利用了金属纳米颗粒（NP）中的局域表面等离子体共振（LSPR）光学现象，显著提高了具有高温稳定性的日盲氮化铝镓金属-半导体-金属光电探测器的性能。我们证明，钯（Pd）纳米颗粒的存在分别使氮化铝镓光电探测器在280nm波长处的光暗电流比（PDCR）、响应度和比探测率显著提高了近600%、300%和462%。在仅32W/cm²的光功率密度和-10V的偏压下，PDCR、响应度和比探测率的最大值分别达到约3×10、2.7A/W和2.4×10¹²Jones。有限时域差分模拟支持了实验观察结果，清楚地表明在氮化铝镓表面修饰的钯纳米颗粒中存在LSPR。详细研究了增强背后的机制，这归因于LSPR诱导的效应，即改善的光吸收、增强的局部电场和LSPR敏化效应。此外，该光电探测器在高达400K的温度下仍能稳定工作，从而展现出商业应用所需的高温稳定性。
