Catalysis

Engineering

Mesoporous material

Materials science

Planar

Computer graphics (images)

Tin oxide

Biochemistry

Computer science

Perovskite (structure)

Chemical engineering

Physics

Hysteresis

Nanotechnology

Perovskite solar cell

Doping

Condensed matter physics

Crystallography

Chemistry

Energy conversion efficiency

Optoelectronics

Nature Communications

Even though the mesoporous-type perovskite solar cell (PSC) is known for high efficiency, its planar-type counterpart exhibits lower efficiency and hysteretic response. Herein, we report success in suppressing hysteresis and record efficiency for planar-type devices using EDTA-complexed tin oxide (SnO2) electron-transport layer. The Fermi level of EDTA-complexed SnO2 is better matched with the conduction band of perovskite, leading to high open-circuit voltage. Its electron mobility is about three times larger than that of the SnO2. The record power conversion efficiency of planar-type PSCs with EDTA-complexed SnO2 increases to 21.60% (certified at 21.52% by Newport) with negligible hysteresis. Meanwhile, the low-temperature processed EDTA-complexed SnO2 enables 18.28% efficiency for a flexible device. Moreover, the unsealed PSCs with EDTA-complexed SnO2 degrade only by 8% exposed in an ambient atmosphere after 2880 h, and only by 14% after 120 h under irradiation at 100 mW cm-2.

High efficiency planar-type perovskite solar cells with negligible hysteresis using EDTA-complexed SnO2