The doping of hydrogenated amorphous silicon and its impact on devices

Abstract Prior to the mid-1970s, most scientists believed that one could not dope amorphous semiconductors since the local environment would adjust to accommodate the normal valence requirements of the dopant atom. However, in 1974 Carlson1 started experiments on the doping of glow-discharge-deposited amorphous silicon that led to the development of amorphous Si solar cells.2 Independently, Spear and LeComber3 showed that glow-discharge-deposited amorphous Si could be doped either p-type or n-type using diborane (B2H6) or phosphine (PH3), respectively, as a dopant feedstock gas in a silane (SiH4) glow discharge.