The Preparation of InAsSb/InSb SLS and InSb Photodiodes by MOCVD

Abstract

ABSTRACTInfrared absorption and photoluminescence have been demonstrated for InAs1-xSbx/InSb strained-layer superlattices (SLS's) in the 8-15 μm region for As content less than 20%. This extended infrared activity is due to the type II heterojunction band offset in these SLS's. The preparation of the first MOCVD grown p-n junction diode was achieved by using dimethyltellurium as an n-type dopant. Several factors, such as background doping and dopant profiles affect the performance of this device. InSb diodes have been prepared using tetraethyltin. The resulting current-voltage characteristics are improved over those of diodes grown previously using dimethyltellurium. Doping levels of 8x1015 to 5x1018cm−3 and mobilities of 6.7x104 to 1.1x104 cm2/Vs have been measured for Sn doped InSb. SLS diode structures have been prepared using Sn and Cd as the dopants. Structures prepared with p-type buffer layers are more reproducible.