Electrical property of iron-related defects in n-type dislocated Czochralski silicon crystal used for solar cells

Abstract

Interactions of iron atoms with dislocations in n-type Czochralski silicon have been studied by combining deep level transient spectroscopy (DLTS) and electron beam induced current (EBIC). The EBIC results indicate that dislocations facilitate the aggregation of iron atoms. The DLTS reveals three levels K1 (E c—0.17 eV), K2 (E c—0.35 eV) and K3 (E c—0.48 eV). The amplitudes of K2 and K3 peaks exhibit extended localized states. The origin of levels K2 and K3 is attributed to iron clusters around dislocations, and the existence of iron clusters in the vicinity of dislocations is further proved.