Current solar cell technologies use semiconductors (prominently silicon), to convert light energy into electricity through the photovoltaic effect (PV). This effect faces thermodynamic constraints that can only be alleviated through complex and expensive material architectures, reaching efficiencies below 40%. Other energy materials, such as wide-bandgap ferroelectrics, can provide an alternative path to photovoltaic devices free from thermodynamic limitations, through the so-called bulk photovoltaic effect (BPV), but suffer from very low light absorption properties. Although the BPV effect is fundamentally restricted to non-centrosymmetric materials, in a breakthrough research result, Alexe and co-workers have demonstrated earlier this year that strain gradients induced by a nano/micro indenter can also be used to activate the BPV effect in nominally centrosymmetric materials with favorable bandgaps for solar absorption. This new effect, termed flexo-photovoltaic (flexo-PV) effect, could lead to a new generation of efficient and cheap flexo-PV solar cells but lacks a theoretical framework. Importantly, it points out an unexpected and nontrivial connection between photovoltaics and mechanics. The main goal of this project is to develop a comprehensive theoretical and advanced computational framework for flexo-PV. We plan to use this framework to develop strain-gradient engineering concepts to extend the flexo-PV effect to large areas in a simple and scalable way, beyond the highly localized strain gradients around the tip of a nano/micro indenter in current proofs-of-concept. This will enable a new generation of solar cells with engineered strain gradients to maximize the flexo-PV effect over large areas.
Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020
Programa Estatal de I+D+i Orientada a los Retos de la Sociedad