Atomic layer deposition (ALD) and chemical vapor deposition (CVD) deposit highly conformal films, and hence are important tools for developing nanostructured solar cells with scalability. Solar cells that utilize Earth-abundant materials are more cost-effective and sustainable. One such material of great interest is Cu2ZnSnS4 (CZTS), which has reached an efficiency of 12.6% in solar cells.
We use ALD and CVD to prepare composite thin films of ZnS/Cu2S, Cu2SnS3 and Cu2ZnSnS4 (CZTS). Our characterization methods include optical spectroscopy, atomic force microscopy, transport measurements, scanning electron microscopy, and energy-dispersive x-ray spectroscopy.
We also collaborate with the Bridges lab, which uses extended x-ray absorption fine structure (EXAFS) to probe the local environment about different atoms and can give very precise ratios of elements using their fluorescence peaks.