Work

Spontaneous Passivation of Hybrid Perovskite by Sodium Ions from Glass Substrates: Mysterious Enhancement of Device Efficiency Revealed

Year: 2017

Type: article

Abstract: The efficiency of a solar cell generally decreases over time due to degradation of the devices. Here we report a spontaneous increase of device efficiency for organic–inorganic hybrid perovskite (OIHP) solar cells after a period of storage that is speculated to be related to the sodium ions (Na + ) diffused from the substrate. The efficiency of a p–i–n planar heterojunction structure device rises from 18.8 to 20.2% after 24 h of storage in nitrogen. The increased efficiency can be explained by the prolonged carrier lifetime and reduced trap density in the OIHP films. The expected contribution by Na + in defect passivation has been evidenced by studying the evolution of the film’s photoluminescence (PL) lifetime, trap density, and device efficiency over storage duration on varied substrates that either contain Na + or do not. The passivation effect of Na + is further identified by the improved PL lifetime observed in the OIHP film made on a silicon substrate with intentionally added Na + .

Source: ACS Energy Letters

DOI: 10.1021/acsenergylett.7b00356

Authors: Cheng Bi, Xiaopeng Zheng, Bo Chen, Haotong Wei, Jinsong Huang

Institutions: University of Nebraska–Lincoln, University of North Carolina at Chapel Hill

Language: English

Topic: Perovskite Materials and Applications

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: green

Funders: Office of Naval Research, Division of Electrical, Communications and Cyber Systems, Air Force Office of Scientific Research