Solubility and Electrical Behavior of Group IV Impurities in Solution Grown Gallium Phosphide

Gall ium phosphide crystals doped with silicon, germanium, or tin were grown from solution by using a thermal gradient technique. At low doping levels nearly all of the tin or silicon atoms act as donors, i.e., substitute on gall ium sites. At higher doping levels the number of tin and silicon atoms substituting on phosphorus sites increases to about 30 % and almost 50%, respectively. In contrast, doping with germanium yields p-type material t the lower doping levels and n-type material at higher doping levels with nearly equal numbers of germanium atoms on both sites at all doping levels. The purpose of this paper is to present the results of experiments dealing with the concentration de-pendence of the electrical activities and solid solubili-ties o2 silicon, germanium, and ti in GaP crystals grown from gallium solution. This work is an exten-sion of similar studies on zinc, sulfur, selenium, an