High-operating-temperature MWIR detectors using type II superlattices

摘要

There is an increasing interest in the development of high operating temperature (HOT) detectors with InAs/Ga(In)Sb Type-II superlattice (T2-SL) material systems. A wide variety of unipolar barrier structures have been investigated and successfully implemented in low-noise device architectures. In this paper, some of our recent work on the development of HOT mid-IR (MWIR) T2-SL photodetectors with interband cascade schemes will be summarized. In these structures, the discrete InAs/GaSb SL absorbers are sandwiched between quantum-engineered electron and hole barriers, which facilitate photovoltaic operation and efficient photo-carrier extraction. Even at its initial stage of development, such an advanced design has led to the demonstration of mid-IR photodetectors with background-limited operation above 150 K (300 K, 2π field-of-view), as well as above room temperature zero-bias operation. Further understanding of the device operation and design principles will also be discussed.