The optoelectronic properties of ultrananocrystalline diamond films (UNCD) grown using N2=0 and 5% in the deposition gas mixture, are investigated by transient photocurrent measurements under nanosecond light pulses, both in planar and sandwich contact arrangements. Independent of contact configuration and N2% value, very similar characteristic times in the 6-7 ns range are detected in the nanosecond range, reflecting a homogeneous distribution of states responsible for such decay times. On a longer time scale, nitrogen addition appears to slow down carrier transport promoting trapping and detrapping processes responsible for single and two power law photocurrent decays in films deposited using N2=5% for sandwich and planar contact arrangements, respectively. Such a result suggests a nitrogen induced transport anisotropy tentatively related to structural modifications occurring at relatively low N2%.
Rossi, M.C., A., M., S., C., P., C., Conte, G., V., R. (2010). Charge carrier transport anisotropy in ultrananocrystalline diamond films. DIAMOND AND RELATED MATERIALS, 19, 238-241 [10.1016/j.diamond.2009.09.007].