Microelectronics Journal 39 (2008) 418–422 Effect of CdTe monolayer insertion on CdZnTe/ZnTe quantum well characteristics T. Kryshtab a,Ã , J.A. Andraca a , L.V. Borkovska b , N.O. Korsunska b , Ye.F. Venger b , Yu.G. Sadofyev c a Instituto Politecnico Nacional-Escuela Superior de Fisica y Matematicas, Av. IPN, Ed. 9, U.P.A.L.M., 07738 Mexico D.F., Mexico b V. Lashkaryov Institute of Semiconductor Physics NASU, Pr. Nauki 41, Kyiv 03028, Ukraine c Lebedev Physical Institute, RAS, Leninskii Pr. 53, Moscow 117924, Russia Available online 6 September 2007 Abstract The effect of CdTe monolayer (ML) insertion on the structural and luminescence characteristics of ZnCdTe/ZnTe quantum well (QW) was investigated by a high-resolution X-ray diffraction (HRXRD) and photoluminescence (PL) methods. The structures were grown by MBE on just-oriented or 31 off (0 0 1) GaAs substrate and contained Zn 0.6 Cd 0.4 Te QW with or without CdTe 1 ML insertion embedded in the middle of QW. HRXRD(0 0 4) diffraction profiles and reciprocal space maps in the vicinity of the (0 0 4) reflection were measured. CdTe insertion led to the shift of QW-related peak to larger angels as well as to significant broadening and disappearance of fringes. The low-temperature PL investigations showed that CdTe insertion resulted in a ‘‘blue’’ shift of the QW PL peak position, in the two times narrowing of the QW PL band and one order of value increase of its intensity. r 2007 Elsevier Ltd. All rights reserved. Keywords: QW; ZnTe; CdTe ML insertion; MBE; HRXRD; PL 1. Introduction ZnTe-based QW structures attract mush attention since they can be used in optoelectronic devices to produce light emission within the middle visible spectral range that cannot be obtained with III–V (red-light) and III-nitride (blue-light) compounds heterostructures. Recently, ZnCdTe/ZnTe p–n junction light-emitting diodes with yellow emission at room temperature were demonstrated [1]. Optically pumped laser in the pure-green region at room temperature has been realized on the base of a ZnCdTe/ZnTe/ZnMgSeTe QW structure [2]. Moreover, yellow and green laser diodes have been fabricated using ZnCdTe/MgZnSeTe [3] and ZnCdSeTe/ZnMgSeTe [4] structures, respectively. However, lifetime of light- emitting devices based on II–VI QWs is too short for practical use. The propagation and multiplication of defects in the active region during device operation are responsible for device degradation. One possible way to overcome the degradation problem is to develop a new structure of the active medium. It was shown that an improvement of device operated characteristics can be obtained by use of ultrathin insertions of narrow band- gap semiconductor material in wide band-gap matrices [5,6]. Room temperature ZnSe-based optically pumped lasers with an extremely low threshold and injection laser diodes were fabricated using a single CdSe ML in an active region. Significantly enhanced degradation stability and improvement of optical characteristics were ascribed to CdSe-based nanoislands observed in the active region [6]. In this work, we present high-resolution X-ray diffrac- tion and photoluminescence studies of the effect of CdTe ML insertion on the structural and luminescence char- acteristics of ZnCdTe/ZnTe QW grown by molecular-beam epitaxy (MBE). ARTICLE IN PRESS www.elsevier.com/locate/mejo 0026-2692/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.mejo.2007.07.024 Ã Corresponding author. Tel.: +52 55 57296000x55321; fax: +52 55 55862825. E-mail address: tkrysh@esfm.ipn.mx (T. Kryshtab).