Spectroscopic investigation of strain induced by compositional variation in bulk InxGa1-xAs crystal grown by MCZM method

Raman scattering (RS), photoluminescence (PL) and energy dispersive X-ray (EDX) experiments have been carried out to investigate residual strain and hence to understand breakage issue in bulk InxGa1-xAs crystal grown by multi component zone melting (MCZM) method. It is found from a comparison that there is a large discrepancy among the RS, PL and EDX results due to the strain induced by compositional variation in the crystal. The strain induced changes in TOGaAs and PL peak positions are found to be 4.04 cm-1 and 0.097 eV, respectively, for the variation of composition from 0.06 to 0.29 from the seed-end to the tail-end of the crystal. By assuming a simple one-dimensional strain distribution, the strain value corresponding to 4.04 cm-1/0.097 eV can be obtained of the order of 10-2, which is large enough for understanding the breakage issue in the crystal investigated here. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)