On the reduced electrical conductivity of radio-frequency sputtered doped ceria thin film by elevating the substrate temperature
Sanghoon Ji, Jihwan An, Dong Young Jang, Youngseok Jee, Joon Hyung Shim, Suk Won Cha
The electrical conductivity of ~200 nm-thick gadolinium-doped ceria (GDC) thin films deposited at various substrate temperatures by radio-frequency sputtering was evaluated in a temperature range of 400 ℃-550 ℃ as an electrolyte for solid oxide fuel cells operated at low temperatures. Morphological, chemical, and crystalline properties were discussed to determine the electrical conductivity; in particular, the electrical conductivity of GDC thin film deposited at 300 ℃ was appreciably lower than that of GDC thin film deposited at 150 ℃. The columnar grain boundaries and the reduced ceria formed during the sputtering process are considered as the major factors leading to the measured results.