Optically detected cyclotron resonance determination of the in-plane effective mass in Ga0471n053As/InP single quantum wells P. Omling Department of Solid State Physics, University of Lund, Box 118, S-221 00 Lund, Sweden C. Wetzel, Al. L. Efros, P. Sobkowicz, A. Moll and B. K. Meyer Physikdepartment E16, TU Munich, D-8046 Garching, F. R. G. AB STRACT Measurements of the in-plane electron effective mass in GaInAs/InP single quantum wells as a function of well thickness using far-infrared optically detected cyclotron resonance (FIR-ODCR) is reported. The FIR-ODCR technique is described, the mechanism of detection is explained, and the experimental results are compared with a theoretical calculation. In the thinnest QW investigated (80 A) the in-plane mass is found to increase by about 50% compared to the bulk GaInAs value. 1. INTRODUCTION The effective mass is a fundamental property in semiconductor physics. The bulk effective mass is almost isotropic in AlGaiAs/GaAs and Ga0 471n0 53As/InP, the materials most frequently used for fabrication of low dimensional structures. This is in many cases motivating the approach to use the bulk value of the effective mass in calculations of two-dimensional (2D) properties such as the quantisation energy. However, in more correct descriptions of two-dimensional electron gas (2DEG) systems or quantum well (QW) systems the effective mass is divided into a parallel mass m* ( (with respect to the growth plane) and a perpendicular mass m*1. These two effective masses have in general different values, and depend critically on the degree of quantisation, i.e. on the width of the confining potential. Even though the theoretical arguments behind the change of the two effective masses with increasing qiantisation is well understood2'3 the experimental verification is not straightforward.4' Only a few investigations have been performed so far and a drawback of the applied techniques, such as far-infrared absorption, is the low sensitivity. Therefore, the samples have to be heavily doped resulting in mass changes due to band-filling effects. In this report we how how the far-infrared optically detected cyclotron resonance (FIR- ODCR) technique8' can be applied on nominally undoped, single quantum wells of Ga0 471n0 53As/InP to determine the in-plane effective mass values in samples where no, or negligible, band-filling effects occur. 2. EXPERIMENTAL The experiments were performed on metal-organic chemical vapour deposition grown O-8194-0836-O/92/$4.OO SPIE Vol. 1675 Quantum Well and Superlattice Physics !V(1992) / 395 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 11/19/2014 Terms of Use: http://spiedl.org/terms