ANALYSIS OF EXCITON ABSORPTION PEAK BROADENING CONTRIBUTIONS IN INGAAS INP MULTI-QUANTUM-WELLS/

The excitonic absorption of InGaAs/InP multi quantum wells prepared by chemical beam epitaxy with different growth conditions and structure parameters are studied in the temperature range 8 to 300 K and in the spectral region where the heavy hole to electron (hh-e) transition cor responding to n = 1 arises. In particular, a lineshape modelling is at tempted using a Gaussian function. The temperature variation of the fu ll width at half maximum (FWHM) is discussed in terms of an intrinsic contribution Gamma(0) plus a thermal broadening due to the interaction with longitudinal optical (LO) phonons. The Gamma(0) value may be con sidered as a helpful parameter to investigate the structural quality o f the samples studied, leading to the observation that absorption spec troscopy is a simple and powerful characterization technique of MQW.