I n   s i t u investigation of the optoelectronic properties of transparent conducting oxide/amorphous silicon interfaces

• Published in: Applied physics letters Vol. 54; no. 21; pp. 2088 - 2090
• Main Authors: Drevillon, B., Kumar, Satyendra, Roca i Cabarrocas, P., Siefert, J. M.
• Format: Journal Article
• Language: English
• Published: 22-05-1989
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.101511

Transparent conducting oxide (TCO)/hydrogenated amorphous silicon (a-Si:H) interfaces are investigated combining kinetic ellipsometry and Kelvin probe measurements. It is shown that the correlation between both in situ techniques allows a detailed description of the optoelectronic behavior of these interfaces. The Schottky barrier at the TCO/a/Si:H interfaces, as revealed by Kelvin probe measurements, is correlated with the chemical reduction of the TCO surface during the early stage of a:Si:H growth, as evidenced by kinetic ellipsometry. In particular, indium tin oxide (ITO) and SnO2 are found to be reduced by the silane plasma at 250 °C. On the countrary, ZnO is found highly resistant upon plasma reduction. The influence of the substrate temperature during a-Si:H deposition is analyzed. Finally, the technical consequences of this study are outlined.