Atomic Layer Deposition

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.