Preparation of InAsSb/InSb SLS and InSb photodiodes by MOCVD.

摘要

Infrared absorption and photoluminescence have been demonstrated for InAs(sub 1-x)Sb(sub x)/InSb strained-layer superlattices (SLS's) in the 8--15 (eta)m 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 in-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 8 (times) 10(sup 15) to 5 (times) 10(sup 18) cm(sup (minus)3) and mobilities of 6.7 (times) 10(sup 4) to 1.1 (times) 10(sup 4) cm(sup 2)/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. 5 refs., 4 figs.