WFU Physics and Chemistry Colloquium
TITLE: “Solution Processing of High-Performance Solar Cells: Opportunities & Technological Challenges”
SPEAKER: Professor David Mitzi
Mechanical Engineering and Materials Science
TIME: Wed. Oct. 4, 2017 at 4:00 PM
PLACE: George P. Williams, Jr. Lecture Hall, (Olin 101)
There will be a reception with refreshments at 3:30 PM in the lounge. All interested persons are cordially invited to attend.
While ever expanding worldwide energy demand necessitates a broad portfolio of energy options, the progressive drop in cost and ubiquitous carbon-free “fuel” for photovoltaic (PV) technologies suggests that this pathway will play a vital role in this mix. Device fabrication involving simple solution-based processing provides one pathway for substantially further reducing cost for PV application. This talk addresses several particularly promising thin-film PV technologies based on solution-processed Cu-In-Ga-S-Se (CIGS) and Cu-Zn-Sn-S-Se (CZTS) chalcogenide absorbers, enabling the fabrication of high-performance absorber layers, with resulting device sunlight-to-electricity power conversion efficiencies of as high as 15%. Key focal points include developing appropriate solution/precursor chemistries, and film deposition and defect engineering approaches. For the relatively new CZTS system, the combination of progressively higher record efficiency, earth abundant starting materials, and lower-cost solution-based processing opens opportunities for development of a potentially pervasive PV technology. In addition, metal-halide perovskite compounds, offering near-ambient temperature solution processing, a high degree of chemical tunability and unprecedented improvement in efficiency to the 20+% level over only a few short years of development, will also be discussed. The three technologies (CIGS, CZTS and perovskites) provide outstanding examples of how solution-based processing may, not only lead to a pathway for low cost PV, but also to performance levels that rival and even beat vacuum-based deposition, which is crucial for these technologies to have market penetration.