The rapid prototyping of textured amorphous surfaces for the graphoepitaxial deposition of CdTe films using focused ion beam lithography

Cadmium telluride films deposited on amorphous substrates exhibit a grain structure characterized by [111]-oriented grains, but where the in-plane grain orientation is randomized due to the absence of epitaxy. Here, we explore the viability of promoting an in-plane grain alignment through graphoepitaxy. Fifteen different substrate surface textures were fabricated using focused ion beam lithography. This approach allows for the side-by-side deposition of surface textures where both the areal extent and depth of the surface features are varied in a systematic manner. CdTe films deposited overtop these textures show grain structures with dramatic variations, revealing that particular length scales have the most pronounced effect on the grain structure.