Growth of isolated and embedded Cu-containing chalcopyrite clusters and nanocrystals by dry processing

Abstract

A dry method for the growth of Cu-containing chalcopyrite nanocrystals on solid substrates is described. The experimental realization of the method relies on decoupling, by means of metal precursors, the two main issues of the growth of highly structured material: on the one hand, the structuring itself of the target material at the desired scale, and on the other hand, the actual chemical process ensuring the quality of the material. In the present approach, the precursors, consisting of species to be incorporated during the process in the final semiconducting compound, control the structuring, whereas chemical vapor deposition methods account for the chemistry of the process. The method proposed has been analyzed at a theoretical level by means of thermochemical calculations, which helped determine the ranges of interest of the experimental parameters involved in the deposition process. By choosing different distributions of Cu precursor deposited on standard glass substrates, nanocrystals, submicrometer polycrystalline dots, or macroscopic clusters of Cu-containing chalcopyrite compounds have been grown, either as isolated units or, alternatively, as embedded structures in a matrix of a binary chalcogenide compound, as a function of processing parameters. Compositional and structural analyses were used to determine the nature of the crystalline phases obtained thereof. Scanning probe techniques were used to characterize the samples at nanometer scale, demonstrating the suitability of the proposed method.