Program Highlights

Solar Cell Enhancement by Ionic Defect Passivation

Jinsong Huang and Xiao Cheng Zeng

Nebraska MRSEC

Organic–inorganic halide perovskites are promising materials for efficient conversion of solar energy to electricity. However, the presence of ionic defects at the surfaces and grain boundaries in there materials are detrimental to both the efficiency and stability of perovskite solar cells. Nebraska MRSEC researchers have shown that quaternary ammonium halides can effectively passivate ionic defects in several different types of hybrid perovskites with negative- and positive-charged components. The defect passivation reduces the charge trap density and elongates the carrier recombination lifetime, boosting the efficiency to a certified value of above 20%. Moreover, the defect healing significantly enhances the stability of films in ambient conditions. These findings provide an avenue to further improve both the efficiency and stability of solar cells. (X. Zheng et al., Nature Energy 2, 17102 (2017) doi:10.1038/nenergy.2017.102).

This research is supported by the National Science Foundation, Division of Materials Research, Materials Research Science and Engineering Program, Grant DMR-1420645.

Quaternary ammonium halides can passivate both cationic and anionic defects, which enhances solar cells efficiency and stability.