p-GaSe Thin Films by the Vacuum Evaporation of Ga₂Se₃

Abstract

Thin films were obtained from the vacuum evaporation of Ga₂Se₃, and were investigated for their electric properties. The obtained results are: 1) The thin films consisted of hexagonal crystalline GaSe, when Ga₂Se₃ was vacuum evaporated on the substrate kept at temperature above 200°C. 2) The crystal line GaSe had a layered structure, its C axis being perpendicular to the substrate plane. 3) For the crystalline growth, Frank-van der Merwe's mechanism was almost matched. 4) The films behaved as p type semiconductors and their acceptor levels were estimated to locate at 0.41-0.44 eV above the valence band. 5) The resistivities of the films were decreased in accordance with increase of the hole mobility, when the substrates had been kept at higher temperature at the vacuum evaporation. 6) The fill factor was 0.32 for a p-n GaSe junction cell obtained by the vacuum evaporation.