The density of states of hydrogenated amorphous silicon was assumed to be either uniform or spatially variable inside the intrinsic layer of p-i-n solar cells. The dependence of the dark current voltage characteristics of amorphous silicon based solar cells with respect to the intrinsic layer thickness and to the mobility gap of a thin interfacial layer grown at the p/i interface was explored using numerical techniques. The results indicated that the reported experimental trends could be adequately explained by the defect-pool model and not by assuming a uniform density of states in the intrinsic layer.

Evidences of the Defect Pool Model in the Dark Current-Voltage Characteristics of Hydrogenated Amorphous Silicon Based p-i-n Devices. A.Sturialea, F.A.Rubinelli: Thin Solid Films, 2008, 516[21], 7708-14