Project Name: Crosscutting Recombination Metrology for Expediting Open-Circuit Voltage Engineering
Funding Opportunity: PVRD
SunShot Subprogram: Photovoltaics
Location: San Marcos, TX
SunShot Award Amount: $1,025,000
Awardee Cost Share: $232,107
Project Investigator: Jian Li

This project is developing a comprehensive characterization methodology for extracting recombination rates in thin-film solar cells as a function of depth into the device. The advanced metrology methods developed as part of this project will ideally allow researchers and manufacturers to identify problem areas in their materials within a few dozen nanometers and correct their procedures accordingly. The proposed methodology will also allow for the viability of certain interfaces and contact structures to be examined at a greater level of detail than has previously been available based on existing optoelectronic methods.


This project will develop crosscutting metrology for characterizing recombination to expedite open-circuit voltage enhancement in thin-film PV technologies. The research team will produce two metrology versions with unprecedented advantages over existing approaches. The first version is a rapid process that is practical but based on select approximations. The process is rapid because it may not require temperature variation and the numerical workload is streamlined, making it suitable for analysis in a manufacturing environment. The second version is an exact-solution that is practical and uses no approximation. The processing time is longer due to requisite temperature dependence. This version is suitable for in-depth analysis in an off-line laboratory research and development environment.


Thin-film PV has long suffered the disadvantage of lacking a metrology to reliably link open-circuit voltage to materials synthesis because recombination is spatially distributed and non-uniform. This project will enable the determination of type-resolved recombination rates at different points in the device layers and make metrology-guided open-circuit voltage engineering a practical reality, removing this long-standing disadvantage for thin-film PV. The successful application of this metrology to thin-film PV modules will catalyze the advancement of open-circuit voltage and module efficiency, reducing the solar levelized cost of energy toward and beyond the $0.06 per kilowatt hour SunShot 2020 goal.