The chalcopyrite material class, typically identified by its most popular alloy Cu(In,Ga)(S,Se)2 , provides exceptionally good semiconductor candidates for solar energy conversion. A key asset of this low-cost thin film solar absorber is its outstanding optical and electronic properties, as demonstrated by CuInGaSe 2 solar cells reaching over 24% power conversion efficiency. The tunable energetics of chalcopyrites also make them well-suited candidates for solar fuels production (e.g. photoelectrochemical water splitting, CO2 reduction), since the position of “energetic bands” can be adjusted to match specific electrochemical potentials and ensure efficient redox chemistry. Recently, we demonstrated that unique optoelectronic properties emerge in chalcopyrites when their microstructure is greatly disrupted. Synthesizing such materials, also known as ordered vacancy compounds (OVC), requires however precise methods to prevent the formation of defects. The ability to model, characterize and engineer such defects in solar materials is of great interest to the scientific community and central to this project.

We plan to explore the syntheses and defect control in chalcopyrite solar cells. Students will be deeply involved in the achievement of the following tasks:

• Synthesize thin film solar materials.

• Characterize materials using various optical spectroscopy and electrical techniques.

• Evaluate the power conversion efficiency of complete solar cells.

We anticipate students on this project to learn and gain skills related to:

• Developing new materials applicable for solar energy conversion.

• Characterization and testing methods of materials.

• Collaborating with faculty and students from both UH and UW

• Potential for summer research experience at UW.

• Giving presentations at seminars and/or symposia.