Comment on ‘‘Temperature limits on infrared detectivities of InAs/InxGa1−xSb superlattices and bulk Hg1−xCdxTe’’ [J. Appl. Phys. 74, 4774 (1993)]

作者：J. Piotrowski, Antoni Rogalski · 发表于：Journal of Applied Physics · 年份：1996 · DOI：10.1063/1.363043 · 被引用次数：37 · 研究领域：Advanced Semiconductor Detectors and Materials、Infrared Target Detection Methodologies、Calibration and Measurement Techniques

Three papers published recently [P. M. Young, C. H. Grein, H. Ehrenreich, and R. H. Miles, J. Appl. Phys. 74, 4774 (1993); G. M. Williams, J. Appl. Phys. 77, 4153 (1995); C. H. Grein, M. E. Flatte, H. Ehrenreich, and R. H. Miles, J. Appl. Phys. 77, 4156 (1995)] concerning the comparison of theoretically predicted performance of HgCdTe photodiodes with InAs/InGaSb superlattice photovoltaic detectors are obscure with respect to optimal selection of HgCdTe photodiode structures. Both Comments [G. M. Williams, J. Appl. Phys. 77, 4153 (1995); C. H. Grein, M. E. Flatte, H. Ehrenreich, and R. H. Miles, J. Appl. Phys. 77, 4156 (1995)] have not noticed the important results of papers published by Humpreys [Infrared Phys. 23, 171 (1983); Infrared Phys. 26, 337 (1986)], who critically reexamined the role of a radiative mechanism in the detection of infrared radiation. To explain our point of view on competition between InAs/InGaSb SLs and ‘‘bulk’’ HgCdTe detectors, we present a generalized model of an infrared photodetector and derive the figure merit of any material for infrared photodetector as the ratio of absorption coefficient to the thermal generation rate. This determines the detectivity of infrared photodetectors. Using that model for the most common n+-p and p+-n long wavelength HgCdTe photodiodes, it is shown that the highest performance can be obtained with a low doping of the base photodiode regions. This means that the previously assumed (Young et al.) highly doped HgCdTe p...