The electron mobility in amorphous silicon under double injection

Abstract

The transport of a pulse of photogenerated excess lectrons has been investigated in a-Si p⁺–i–n⁺ junctions under forward bias in the presence of strong double injection. It is found that the electron drift mobility is completely independent of forward current densities of up to 0·33 A cm⁻². The results disagree with previous work of Silver et al., who observed an appreciable increase in electron mobility in the same range of current densities. It is suggested that the experimental disagreement arises from problems inherent in the voltage-step technique of mobility measurement used by these authors.