Photoconductivity and Photoluminescence of Amorphous Carbon Nitride a-CNx Films Prepared by the Layer-by-Layer Method

Abstract

ABSTRACTAmorphous carbon nitride films a-CNx, which made in our laboratory, show high photosensitivity Ps that is a ratio of photoconductivity σp and dark-electrical conductivity σd Maximum Ps of a-CNx is about 5×106 which is about 50 times larger than that of hydrogenated amorphous silicon a-Si:H.We have succeeded to observe photoconductivity spectra where photoconductivity starts nearly at 2 eV and saturates at 3 eV. Then σp increase again at 3.7 eV up to 6.2 eV. The dependence of σp on excitation energy and intensity is observed. Photoluminescence spectrum is also obtained which have a spectrum from infrared of 0.8 eV up to ultraviolet of 3.5 eV. Using these data together with photothermal deflection spectra, we have presented a refined model of the electronic density of states for LLa-CNx.