Zn_xCd_1–xSe/Zn_x′Cd_y′Mg_{1–x′–y′}Se multi‐quantum well structures for intersubband devices grown by MBE

Abstract

Abstract Quantum well infrared photodetectors (QWIPs) from wide bandgap II–VI compounds are promising as high quantum efficiency detectors in the mid‐IR. A series of Cl‐doped Zn x Cd (1– x ) Se/Zn x ′ Cd y ′ Mg (1– x ′– y ′) Se multiple‐quantum‐wells (MQW) with different quantum well (QW) thicknesses have been grown by MBE lattice‐matched to InP substrates. The high material quality of the samples was demonstrated by X‐ray diffraction (XRD), steady‐state photoluminescence (PL), and time‐resolved photoluminescence ( t ‐PL) measurements. Contactless electroreflectance (CER) measurements were performed to investigate high order transitions within the QWs. From these transitions, intersubband transition energies were predicted and compared with the theoretical calculations, a very useful result for device design. Our results indicate that this material system is very promising for intersubband device applications such as QWIPs operating in the 3–5 µm region. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)