Nanoscale engineering of solution-processed CdTe solar cells using nanocrystalline precursors

Abstract

We have furthered the development of CdTe nanocrystals (NCs) to create bulk, sintered films for ink-based solar cells. Here, respectable efficiencies of >10% have been achieved in devices where CdTe tetrapods are spincoated from pyridine, treated with CdCl2 and briefly annealed. We have inserted these NC-based CdTe layers into more than three device geometries with various contact layers. In one structure, we determine that there is a unique interface that forms between the ITO layer and CdTe layer providing excellent ohmic hole contact after a brief light soak in forward bias. Moreover, the devices have an impressive blue-response in comparison to standard CdTe solar cells despite having the junction at the back of the optical path rather than as a window layer.