Engineering carrier lifetimes in type-II In(Ga)Sb/InAs mid-IR emitters

Type-II In(Ga) Sb quantum-confined structures in InAs matrices offer a potential material system for wavelength flexible, high-efficiency, surface-emitting mid-infrared sources. In this work, the authors investigate the carrier dynamics in this material system and demonstrate a number of techniques for engineering carrier lifetimes in such emitters. Samples are grown by molecular beam epitaxy and optically characterized using temperature dependent Fourier transform infrared spectroscopy and mid-infrared time-resolved photoluminescence. The authors investigate both In(Ga) Sb quantum wells and quantum dots, and demonstrate significant improvements in isolated quantum well emitter carrier lifetimes by controlling quantization in the conduction band, or alternatively, by the formation of InGaSb quantum dot structures in InAs matrices. The authors correlate the engineered improvement in carrier lifetime with the emitters temperature performance of our emitters. (C) 2016 American Vacuum Society.