Chemical Approaches to Addressing the Instability and Toxicity of Lead-Halide Perovskite Solar-Cell Absorbers

A class of materials called lead-iodide perovskites has recently been identified as extremely promising absorbers for low-cost and high-efficiency solar cells. Impressively, efficiencies of solar cells employing these perovskite absorbers have reached commercially viable values in just six years. Despite this remarkable progress in device manufacture, the materials' inherent instability and toxicity may impede their large-scale use. In this talk, I will discuss the sources of these problems and our efforts at overcoming them using synthetic chemistry.

The material's extreme water sensitivity remains a problem for large-scale device fabrication and their long-term use. The toxicity of lead is also a primary concern for the wide-scale use of this technology, particularly in light of the material's water solubility, which greatly increases contamination risks. I will present new materials synthesized in our labs to address these issues. I will also discuss light induced changes that occur in this material, which impede high voltages from being realized in perovskite devices. I will suggest methods to mitigate these effects, including the use of mechanical compression to change the photophysical properties of these compressible solids.

Speaker: hema Karunadasa, Stanford