EAGER: Structural Development of Organometal Halide Perovskites for Thin-film Photovoltaics

Princeton University, Princeton NJ

Investigators

Abstract

Abstract: Nontechnical: The ramping energy demand - spurred by global economic growth, and so far largely met by conventional energy sources - will increasingly strain society through soaring oil prices, pollution, and destabilizing climate change. Solar energy is amongst the top contenders as a viable alternative energy source. The current front-runner for solar power generation is crystalline silicon photovoltaics. With the promise of substantially lower processing and manufacturing costs and rapidly increasing efficiencies; thin-film photovoltaics based on organometal halide perovskites promise to be attractive alternatives. Yet, there are substantial technological bottlenecks that prevent the wide-scale deployment of thin-film perovskite photovoltaics. Among them are device stability and the widespread variability in performance within a single batch and between batches of devices, which have been attributed to the morphology of the perovskite active layers. This EAGER proposal aims to elucidate the structural development of thin-film perovskites, the results of which should facilitate a transformative improvement in device performance and stability. Technical: Structural heterogeneities in perovskite thin films span multiple length scales; its development is rich and complex and highly sensitive to processing conditions. The structure development of thin films perovskite is simultaneously taking place with an ongoing chemical reaction that induces the perovskite formation. Leveraging the principal investigator's experience in decoupling film formation and structure development in polymer and organic electrically active materials, they will quantify the kinetics of perovskite active layer formation, with which they will elucidate the mechanism and impart control over the process, using a combination of in- and ex-situ x-ray diffraction as well as high-resolution microscopy techniques. The processing-structure-function relationships gleaned from this undertaking will bring about approaches to stabilize the desired morphology and thus improve the stability and reliability of perovskite photovoltaics. This EAGER project is highly interdisciplinary and vertically integrated. The students involved will have first-hand exposure to chemical syntheses of perovskites and their precursors; quantitative structural characterization and analyses; and device fabrication and testing.