Over the past eight years, there has been a steady and appreciable increase in power conversion efficiency of organometal halide perovskite solar cells. The relatively high efficiency of these solar cells combined with their ability to be processed using simple solution-based methods, make perovskite solar cells a promising candidate as a solar energy solution. However, perovskite solar cells suffer from a lack of mechanical reliability and chemical stability especially compared to existing solar technologies like silicon, cadmium telluride, and copper indium gallium diselenide devices.
To help improve the chemical instabilities of perovskite solar cells, I am working on the development of thin film barrier layers which prevent degradation by inhibiting the diffusion of water and the volatilization of the perovskite itself in elevated temperatures. We use atmospheric, open-air plasma deposition in order to deposit our thin film barriers, as it is a scalable process, which uses chemical radicals and UV light to deposit high quality, dense films at lower temperatures. The eventual goal is to ensure that the efficiency of the solar cell does not drop below 90% of its initial efficiency after 1000 hours in an 85oC and 85% relative humidity environment.
Another research area I am actively exploring is building flexible perovskite solar cells on metal foil substrates. Flexible substrates are an ideal fit for a roll-to-roll processing line which is necessary for scaling up the manufacturing of solar cells. Metal foil substrates also offer the added advantage of retaining its mechanical integrity in a much larger temperature window than other flexible polymer substrates. The larger temperature window is very useful because many layers in a standard perovskite solar cell device stack require processing at temperatures > 300oC. By developing an efficient perovskite device architecture on metal foil, we are making progress towards enabling perovskite solar cells as a viable solution for solar energy.