EFFECTIVE MASSES AND EVIDENCE FOR ALLOY DISORDER EFFECTS IN GAXIN1-XASYP1-Y INVESTIGATED BY SHALLOW DONOR PHOTOCONDUCTIVITY

An investigation is reported of shallow donor photoconductivity for four compositions in the alloy series Ga//xIn//1// minus //xAs//yP//1// minus //y (y equals 0. 22, 0. 56, 0. 83, 1. 0). The sample peak mobilities exceed 1. 5 m**2V** minus **1s** minus **1. A linear effective mass variation through the alloy range is found to be most consistent with the experimental data. This is at variance with the predictions of K. P theory. Possible reasons for this are discussed.