title: Solution-processed sintered nanocrystal solar cells via layer-by-layer assembly.
abstract: Solar cells made by high temperature and vacuum processes from inorganic semiconductors are at a perceived cost disadvantage when compared with solution-processed systems such as organic and dye-sensitized solar cells. We demonstrate that totally solution processable solar cells can be fabricated from inorganic nanocrystal inks in air at temperature as low as 300 °C. Focusing on a CdTe/ZnO thin-film system, we report solar cells that achieve power conversion efficiencies of 6.9% with greater than 90% internal quantum efficiency. In our approach, nanocrystals are deposited from solution in a layer-by-layer process. Chemical and thermal treatments between layers induce large scale grain formation, turning the 4 nm CdTe particles into pinhole-free films with an optimized average crystallite size of ∼70 nm. Through capacitance-voltage measurements we demonstrate that the CdTe layer is fully depleted which enables the charge carrier collection to be maximized.
authors: CSIRO, Materials Science and Engineering, Bayview Avenue, Clayton, Victoria, 3168, Australia. Jacek.Jasieniak@csiro.au
authors: Jacek
authors: J
authors: Jasieniak
authors: Brandon I
authors: BI
authors: MacDonald
authors: Scott E
authors: SE
authors: Watkins
authors: Paul
authors: P
authors: Mulvaney