Composite formation in CdSe:CuSe nanocrystal films, charge transport characteristics and heterojunction performance.

The use of nanocrystals as materials for potential technological applications depends on tailoring their properties through intentional doping with external impurities. We have used a new technique to synthesize nanocrystal thin films of CdSe:CuSe containing different weight percentages (wt%) of CuSe. The films were deposited on glass substrates at room temperature by co-evaporation of CdSe and CuSe powder in nitrogen gas at a pressure larger than that required for conventional thin film deposition. The films consisted of nanograins of CdSe doped with CuSe (, nanograins of Cd CuSe where is the atom% of CuSe doped into CdSe) for lower wt% of CuSe, and nanocomposites of Cd CuSe and CuSe for higher wt% of CuSe. An energy band diagram built using the Anderson model was used for discussing the heterojunction characteristics of the junction between nanograins of Cd CuSe and CuSe. To investigate the usefulness of the nanocrystal thin films of CdSe:CuSe for practical applications, the - characteristics of p-p and p-n hetero-junctions formed by the films respectively with nanostructured films of similarly deposited CuSe and CdSe films were studied.