Time-of-flight measurement of hydrogenated amorphous GaP

Abstract

Measurements on the time-of-flight for hydrogenated amorphous gallium phosphide, a-Ga rP:H with different values of r and different doses of hydrogen atoms, have been carried out in an attempt to evaluate the drift mobilities of electrons and holes in the materials, where r is the mole ratio of Ga to P. The mobilities are increased, when the amount of dosed hydrogen atoms is increased and the value of r approached to unity. The value of the electron drift mobility in a-GaP:H at 300 K is as high as about 2.5 × 10 −2 cm 2/Vs, which is comparable with that of electrons in a-Si:H measured by Shirafuji ea. The drift mobility of holes in a-Ga rP:H is comparable with that in a-Si:H obtained by Krag et al.