Towards defect-free thin films of the earth-abundant absorber zinc phosphide by nanopatterning
Simon Escobar Steinvall, Elias Z. Stutz, Rajrupa Paul, Mahdi Zamani, Nelson Y. Dzade, Valerio Piazza, Martin Friedl, Virginie de Mestral, Jean-Baptiste Leran, Reza R. Zamani, Anna Fontcuberta i Morral
Abstract
), a promising earth-abundant absorber. The ideal growth conditions are elucidated, and the nucleation of single-crystal nanopyramids that subsequently evolve towards coalesced thin-films is demonstrated. The zinc phosphide pyramids exhibit room temperature bandgap luminescence at 1.53 eV, indicating a high-quality material. The electrical properties of zinc phosphide and the junction with the substrate are assessed by conductive atomic force microscopy on n-type, p-type and intrinsic substrates. The measurements are consistent with the p-type characteristic of zinc phosphide. Overall, this constitutes a new, and transferrable, approach for the controlled and tunable growth of high-quality zinc phosphide, a step forward in the quest for earth-abundant photovoltaics.