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

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 I 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.