Final Report Summary - NANOENABLEDPV (Novel Photovoltaics Enabled by Nanoscience)
The NanoEnabledPV program showed that standard efficiency calculations in isolated nanoscale solar cells are meaningless. It developed the integrating sphere microscopy characterization platform that allowed for the determination of intrinsic properties that allow for comparison between different nanostructured solar cells and state-of-the-art commercial devices. Furthermore, the program showed that the intrinsic light concentration shown by most nanomaterials – the so-called “nanoantenna effect” – does not necessarily lead to increased efficiency limits, an important difference from bulk solar cells. Instead, the angular response of the nanostructure is the key determining factor for the efficiency limit. This program also demonstrated that surface charges, for example induced by charged oxide layers, can be used to locally dope nanostructures, leading to improved performance, reproducibility and stability for several types of solar cells and solar fuel devices. The NanoEnabledPV program demonstrated several novel and scalable methods for making single-crystalline nanostructures with controlled dimensions including nanoextrusion and nanocube synthesis, assembly and epitaxy. Finally, the program investigated some of the peculiar properties of halide perovskite materials, using nanostructures and nanocharacterization to aid in the understanding.