Wurtzite-derived ternary I–III–O(2) semiconductors

Ternary zincblende-derived I–III–VI(2) chalcogenide and II–IV–V(2) pnictide semiconductors have been widely studied and some have been put to practical use. In contrast to the extensive research on these semiconductors, previous studies into ternary I–III–O(2) oxide semiconductors with a wurtzite-derived β-NaFeO(2) structure are limited. Wurtzite-derived β-LiGaO(2) and β-AgGaO(2) form alloys with ZnO and the band gap of ZnO can be controlled to include the visible and ultraviolet regions. β-CuGaO(2), which has a direct band gap of 1.47 eV, has been proposed for use as a light absorber in thin film solar cells. These ternary oxides may thus allow new applications for oxide semiconductors. However, information about wurtzite-derived ternary I–III–O(2) semiconductors is still limited. In this paper we review previous studies on β-LiGaO(2), β-AgGaO(2) and β-CuGaO(2) to determine guiding principles for the development of wurtzite-derived I–III–O(2) semiconductors.