Compositional dependence of electrical properties of GaInAsSb quarternary alloy and novel structure of infrared detector

III-V antimonide compounds are of great interest for their applications, such as optical communication, environmental protection, remoting sensing of atmospheric and IR focal plane array for imaging. In this work, MOCVD growth and characterization of GaSb-rich and InAs-rich GaInAsSb quaternary alloy on GaSb substrate are investigated. The optimal growth temperature for InAs-rich GaInAsSb is a little lower than that for GaSb-rich films owing to the different melting points between these two kinds of epilayers. With the aspect of electrical property, there are two types of electrical conduction in the whole range of composition. InAs-rich GaInAsSb epilayers display n-type conduction while GaSb-rich films p-type. The origin of these two kinds of electrical conduction is believed to be related the intrinsic defects in the epilayers. A new structure of IR detector is proposed according to the different electrical conductions of GaInAsSb epilayers in the different range of composition. It is expected that the performance of the photodiode could be improved.