Band gap and activation energy in amorphous silicon doping-modulated superlattices

Abstract

It has been found that both the activation energy and optical energy gap of amorphous silicon doping-modulated nipi... superlattices vary consistently with i layer thickness. There is a pronounced maximum at an i layer thickness of approximately 14 nm. The occurrence of this maximum, and the general variation, correspond exactly with the behavior of the persistent photoconductivity for the structures. The results are explained in terms of the development of deep trap boron-phosphorus complexes which are rendered shallow by hydrogen accretion.