AlxGa1-xN-based back-illuminated solar-blind photodetectors with external quantum efficiency of 89%

作者：Cicek E; McClintock R; Cho C Y; Rahnema B; Razeghi M^*

来源：Applied Physics Letters, 2013, 103(19): 191108.

DOI：10.1063/1.4829065

We report on high performance AlxGa1-xN-based solar-blind ultraviolet photodetector (PD) array grown on sapphire substrate. First, high quality, crack-free AlN template layer is grown via metalorganic chemical vapor deposition. Then, we systematically optimized the device design and material doping through the growth and processing of multiple devices. After optimization, uniform and solar-blind operation is observed throughout the array; at the peak detection wavelength of 275 nm, 729 mu m(2) area PD showed unbiased peak external quantum efficiency and responsivity of similar to 80% and similar to 176 mA/W, respectively, increasing to 89% under 5 V of reverse bias. Taking the reflection loses into consideration, the internal quantum efficiency of these optimized PD can be estimated to be as high as similar to 98%. The visible rejection ratio measured to be more than six orders of magnitude. Electrical measurements yielded a low-dark current density: <2 x 10(-9) A/cm(2), at 10 V of reverse bias.

• 出版日期2013-11-4
• 单位西北大学