Gwen Williams Prize 2017-2018 Recipients
Development of Lead- and Tin-Based Perovskite Solar Cells
Dr. Brandon Burnett, Chemistry
Dr. Kristin Rabosky, Physics
As large-scale deployment of solar installations increase, the need for solar energy conversion materials that are earth-abundant and non-toxic grows. A new material, perovskites, offers the opportunity for an earth-abundant, non-toxic material that is cost effective to synthesize through solution processing techniques available here at Weber State University (WSU). Perovskites have rapidly grown to high efficiencies since their initial appearance in solar research laboratories in 2009. These materials show much promise, but suffer from degradation that currently holds them back from commercial development. WSU researchers initially made perovskite materials using methylammonium and lead iodide solutions. The researchers optimized these materials to achieve a nanocrystalline microstructure necessary for the conversion energy of 1.9 electron volts. This is comparable to the best in the field, which is between 1.5 and 1.7 electron volts. The researchers used this synthetic technique to create a working solar cell (see Figures 1a and 1b). Now the WSU researchers are working on optimizing each layer in order to increase the efficiency of the solar cell by using the synthetic strategy of chemical vapor deposition. This changes the macroscopic and microscopic structure of the film. These new films are more amorphous than the previous method, which is more optimal for solar cell applications (see Figure 2). The researchers also are working on replacing each layer with the most environmentally friendly and non-toxic material possible. This includes making the perovskite material out of tin instead of lead, using nickel oxide for the hole conducting layer instead of an expensive conductive polymer, and optimizing the titanium dioxide layer.