CZTSe devices fabricated from CZTSSe nanoparticles

To understand and control the growth paths of kesterite based CZTSe films as prepared from kesterite nanoparticles we investigate films prepared from different chalcogenide ratios in the initial nanoparticles. To do so we introduce a new method for producing kesterite nanocrystals with controlled ratios of sulfur and selenium. Final CZTSe devices are prepared from these nanoparticles with total area solar power conversion efficiencies up to and exceeding eight percent (see Fig. 1). All devices made from selenizing nanoparticles that contained sulfur showed efficiency greater than six percent while pure selenide nanoparticles resulted in non-performing devices.