Crystal growth and properties of group IV doped indium phosphide

Abstract InP crystals have been grown from the melt by the high pressure liquid encapsulation technique. A study of the segregation of group IV elements based on measurements of free electron concentrations in doped crystals indicates that the mean effective distribution coefficients for Ge and Sn are 2.4 × 10 −2 and 2.1 × 0 −2 respectively. Whereas doping with Ge and Sn gave high quality and reproducible n-type crystals, controlled doping experiments using Si and Pb were not successful. The role of these latter elements together with that of C is discussed. The characteristic photoluminescence spectra of these doped crystals were measured at 77°K, and in conjunction with the electrical and chemical evidence thepeaks were assigned to specific impurity/vacancy interactions. The highest energy peak at about 1.41 eV is associated with donors and is sensitive to Ge and Sn doping, while the acceptor level appears to lie at 1.37 eV. The peaks at 1.32 eV and 1.35 eV are attributed to the effects of growth from B 2 O 3 and copper doping respectively, and the broad peak between 1.12 and 1.20 eV may be associated with phosphorus vacancies.