We present results from both experimental and theoretical studies of single and double carrier injection into amorphous silicon alloys. For biases above approximately half the built‐in potential double carrier injection in forward biasedp‐i‐ndiodes leads to higher currents than are obtained for single carrier injection inn‐i‐ndiodes. Single carrier injection was found to depend mainly on the density and distribution of localized states in the gap, whereas double injection currents are also very dependent on the recombination kinetics and the carrier band mobilities. Analysis of experimental results suggests that for an electron band mobility of 20 cm2/V sec the hole band mobility is approximately 4 cm2/V sec.