Influence of oxygen impurity in the intrinsic layer of amorphous silicon solar cells

Abstract
The influence of oxygen impurity in the i layer of hydrogenated amorphous silicon (a-Si:H) solar cells is studied. At the initial state, the dark conductivity, and photoconductivity of a-Si:H films increase and the conversion efficiency of the solar cells drops as the oxygen concentration increases. After the light soaking, these film properties become independent of the oxygen concentration, but the conversion efficiency of a-Si:H solar cells is still influenced by the oxygen impurity. The dominant effect of the oxygen impurity in a-Si:H solar cells is a modification of the electric field distribution in the i layer, due to the donorlike states created by oxygen.