The properties of cadmium tin oxide thin-film compounds prepared by linear combinatorial synthesis

摘要

SnO_2 and CdO films with high electrical and optical quality have been produced by using low-pressure metal-organic chemical vapor deposition. Based on the knowledge gained from binary oxide formation, linear combinatorial synthesis is used to study the ternary oxide (Cd-Sn-O) compound. Compositional, structural, electrical, and optical properties of the films are found to vary-along the reactant gas flow direction. The crystal structure indicates that the CdO-like films are formed near the location of gas injection and SnO_2-like films near the end of the deposition zone. As composition and structure change, the carrier concentration varies around 10~(20) cm~(-3), and the mobility increases from less than 1 to ～ 60 cm~2 V~(-1) s~(-1). The optical bandgap of the films also increases from ～ 2.75 to 3.65 eV as composition moves from CdO-like films to SnO_2-like films.