Abstract Submitted for the MAR13 Meeting of The American Physical Society Comparative Study on Intersubband Absorption in AlGaN/GaN and AlInN/GaN Heterostructures Grown on Low-Defect Substrates

Submitted for the MAR13 Meeting of The American Physical Society Comparative Study on Intersubband Absorption in AlGaN/GaN and AlInN/GaN Heterostructures Grown on Low-Defect Substrates COLIN EDMUNDS, LIANG TANG, JIAYI SHAO, DONGHUI LI, GEOFF GARDNER, MICHAEL MANFRA, OANA MALIS, Purdue University, ANDREW GRIER, ZORAN IKONIC, PAUL HARRISON, University of Leeds, DIMITRI ZAKHAROV, Brookhaven National Laboratory — Intersubband (ISB) devices utilizing III-nitrides have attracted attention for nearand far-infrared optoelectronic applications. However, the lattice mismatch between GaN and commonly used substrates results in a high defect density that hinders the vertical transport required for these devices. Furthermore, most devices in the literature utilize AlGaN/GaN heterostructures for which there is no lattice-matched alloy composition. Due to this lattice mismatch, AlGaN is not ideal for the development of complex devices such as quantum cascade lasers that often require active-region thicknesses on the order of microns for efficient operation. Fortunately, exact lattice matching occurs in AlInN/GaN heterostructures at roughly 18% In composition. To investigate the challenges of lattice-matched nitrides, we presents a comparative study of ISB absorption in high-quality AlGaN/GaN and near lattice-matched AlInN/GaN heterostructures grown by molecular-beam epitaxy on low-defect free-standing GaN substrates. Experimental measurements of transition energy, integrated absorbance and linewidth were compared to theoretical predictions that included many-body effects, interface roughness and calculations of the transition lifetime. Colin Edmunds Purdue University Date submitted: 08 Nov 2012 Electronic form version 1.4