Patterned Growth of CdTe Solar Cells

The direct band gap materials CdTe is presently used for thin film polycrystalline solar cells, but has not produced efficiencies nearly as high as predicted.  One of the reasons that this optimal efficiency has not been obtained is that grains near the junction are not uniform in size, shape and orientation leading to poorly functioning  regions on a cell which can seriously degrade performance.  A technique is described to produced much more uniform grains of CdTe using a pattern to confine crystal growth in one direction.  This novel technique and the improvements in cell performance were measured and will be discussed.