异质结 PIN 光探测器可分为单异质结光探测器(SHPD)和双异质结光探测器(DHPD),二者在量子效率、频率响应和暗电流方面存在差异。当 SHPD 光敏面半径为 10μm 且 P 区厚度与电子扩散长度之比小于 0.2 时,其量子效率减小的幅度小于 0.32%,带宽增加约 0～4%;对于由体效应决定的暗电流,SHPD 略优。由此得到当光敏面积较小和 P 区厚度较薄时,SHPD 与 DHPD 性能相当的结论,为高性能宽带光纤网高速光探测器的设计提供了依据。 Heterojunction PIN photodetectors can be classified into single heterojunction photodetector (SHPD) and double heterojunction photodetector (DHPD), both of which have differences in quantum efficiency, frequency response and dark current. When the radius of the photosensitive surface of SHPD is 10μm and the ratio of the thickness of the P region to the electron diffusion length is less than 0.2, the quantum efficiency decreases by less than 0.32% and the bandwidth increases by about 0% ~ 4%. For the dark current determined by the bulk effect, SHPD Slightly better. The conclusion that the performance of SHPD and DHPD are equivalent when the photosensitive area is smaller and the thickness of P region is thinner is obtained, which provides the basis for the design of high-performance broadband optical fiber network high-speed photodetector.