Optical and electrical properties of InAlAs/AlAsSb type II quantum well structures grown by molecular beam epitaxy

In0.52Al0.48As/AlAs0.56Sb0.44 type II multiple quantum well (MQW) layers lattice-matched to InP substrates were grown by molecular beam epitaxy (MBE). Light emission at 0.91-0.97 mu m was observed at 77 K, which arises from the recombination between electrons in the InAlAs layers and holes in the AlAsSb layers across the type IT heterointerface. The conduction band discontinuity Delta E-c at Gamma point is estimated to be 1.25 eV from the InAlAs well-width dependence of the emission energy. In addition, an InAlAs/AlAsSb double barrier resonant tunneling diode was fabricated, which shows a clear negative differential resistance at 77 K. (C) 1998 Elsevier Science B.V. All rights reserved.