High performance Perovskite/CIGS tandem solar cells

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Abstract Non-Technical: The sun provides clean and abundant energy source for human being, but solar energy has not been widely used due to the high cost. The key to achieving affordable solar photovoltaic (PV) technologies is to develop techniques that offer both high performance and low material and processing costs. This research will combine the strength of two types of high performance thin film solar cell technologies - copper indium gallium diselenide (CIGS) solar cells and organic-inorganic hybrid perovskite solar cells to realize tandem solar cells and address key issue. The research will significantly enhance the thin film solar cell efficiency from 20% to 30% and still keep low cost. The proposed research represents a new front in solar cell research society. It will impact national and global efforts in developing new and sustainable energy strategies and technologies, thus impacting the nation's economy and improving environmental quality by reducing the use of fossil fuels. The education component of in this project offers students (from high school to graduate-level) the opportunity to experience all of these trainings and learn the skills to face future scientific challenges. This project also provides a platform for undergraduate training and showcases the importance of renewable energy to society. Technical: The objective of this research is to advance solution processed perovskite/CIGS tandem solar cell technology by reducing thermalization losses of hot carriers generated by photons with larger energies than the bandgap, toward high performance (a target efficiency of 30%). The approach is to design and synthesize both perovskite and CIGS subcells with high performances and spectrum-matched absorption, and a tunnel junction with minimal optical and electric losses, based on full consideration of charge generation, charge separation and transport/collection in a monolithic configuration. The centerpiece of technical approach includes: (1) perovskite solar cell with high PCEs and spectrum-matched absorption will be designed and synthesized; detailed structural and spectroscopic characterizations will be performed, which form the foundation for device fabrication; (2) high performance inorganic CIGS solar cell will be applied to cover the Near-IR (from 800nm to 1200nm) portion; (3) single junction devices based on the materials in the two spectral ranges will be fabricated to achieve optimized performance; charge generation, charge separation and transport mechanism in these devices will be studied; (4) novel nano-functional interlayer and novel geometry of hybrid tandem solar cells will be developed to maximize solar energy conversion; (5) solution processed transparent electrodes will be will be developed to realize all solution process hybrid tandem solar cells. Upon success, this will be the first solution processed solar cell reaching 30% efficiency mark, which is an important milestone for low-cost manufacturing of high efficiency solar cell. This project is jointly funded by the Electronics, Photonics, and Magnetic Devices (EPMD) Program in the Division of Electrical, Communications and Cyber Systems (ECCS) and the Electronic and Photonic Materials (EPM) Program in the Division of Materials Research (DMR).