High-sensitivity 8- to 14-μm HgCdTe photodetectors operated at ambient temperature

作者：Waldemar Gawron, Krzysztof Adamiec, Krzysztof Jóźwikowski, Antoni Rogalski · 发表于：Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 年份：2000 · DOI：10.1117/12.382110 · 被引用次数：3 · 研究领域：Advanced Semiconductor Detectors and Materials、Conferences and Exhibitions Management

This paper presents analysis of theoretical performance and experimental data of small size non-cooled long-wavelength multiple junction devices based on complex 2D Hg1-xCdxTe heterostructures. An original iteration scheme was used to solve the system of non-linear continuity equations and Poisson equation and to determine the performance of devices. All quantities are expressed as the functions of electric potential and Fermi quasi-levels. The results of calculations are presented as the maps showing spatial distribution of absorption coefficient and photoelectrical gain for two types of photodiode configurations: n+-on-p and p-on-n. This approach helps to understand specific features of the devices and optimize their performance. The simulations show that suitable choice of diode configuration limits reverse sign photovoltages in the contacts between p and n regions of the device. The multiple junction devise based on backside illuminated p-n photodiode were fabricated using LPE technique. The photovoltaic devices were prepared by connection in series of small area detectors. Another possibility of device technology is a stack of individual very thin photovoltaic detectors. It appears that the total thickness of the structures should be close to optimum thickness equal to 1.23/(alpha) and the thickness of lightly doped region of each element should be lower than the diffusion length. The theoretical predictions of detector performance have been compared with the experimenta...