Dual Interfacial Design for Efficient CsPbI2Br Perovskite Solar Cells with Improved Photostability

Tian J, Xue Q, Tang X, Chen Y, Li N, Hu Z, Shi T, Wang X, Huang F, Brabec C, Yip HL, Cao Y (2019)

Publication Language: English

Publication Status: Published

Publication Type: Journal article

Publication year: 2019

Journal

Advanced Materials Wiley-VCH Verlag

Book Volume: 31

Pages Range: e1901152

Article Number: 1901152

Journal Issue: 23

DOI: 10.1002/adma.201901152

Abstract

A synergic interface design is demonstrated for photostable inorganic mixed‐halide perovskite solar cells (PVSCs) by applying an amino‐functionalized polymer (PN4N) as cathode interlayer and a dopant‐free hole‐transporting polymer poly[5,5′‐bis(2‐butyloctyl)‐(2,2′‐bithiophene)‐4,4′‐dicarboxylate‐alt‐5,5′‐2,2′‐bithiophene] (PDCBT) as anode interlayer. First, the interfacial dipole formed at the cathode interface reduces the workfunction of SnO2, while PDCBT with deeper‐lying highest occupied molecular orbital (HOMO) level provides a better energy‐level matching at the anode, leading to a significant enhancement in open‐circuit voltage (Voc) of the PVSCs. Second, the PN4N layer can also tune the surface wetting property to promote the growth of high‐quality all‐inorganic perovskite films with larger grain size and higher crystallinity. Most importantly, both theoretical and experimental results reveal that PN4N and PDCBT can interact strongly with the perovskite crystal, which effectively passivates the electronic surface trap states and suppresses the photoinduced halide segregation of CsPbI2Br films. Therefore, the optimized CsPbI2Br PVSCs exhibit reduced interfacial recombination with efficiency over 16%, which is one of the highest efficiencies reported for all‐inorganic PVSCs. A high photostability with a less than 10% efficiency drop is demonstrated for the CsPbI2Br PVSCs with dual interfacial modifications under continuous 1 sun equivalent illumination for 400 h.

Authors with CRIS profile

Xiaofeng Tang Institute Materials for Electronics and Energy Technology (i-MEET) Ning Li Institute Materials for Electronics and Energy Technology (i-MEET) Christoph Brabec Institute Materials for Electronics and Energy Technology (i-MEET)

Involved external institutions

Lawrence Berkeley National Laboratory (LBNL) US United States (USA) (US) South China Normal University / 华南师范大学 CN China (CN) Jinan University CN China (CN)

How to cite

APA:

Tian, J., Xue, Q., Tang, X., Chen, Y., Li, N., Hu, Z.,... Cao, Y. (2019). Dual Interfacial Design for Efficient CsPbI2Br Perovskite Solar Cells with Improved Photostability. Advanced Materials, 31(23), e1901152. https://dx.doi.org/10.1002/adma.201901152

MLA:

Tian, Jingjing, et al. "Dual Interfacial Design for Efficient CsPbI2Br Perovskite Solar Cells with Improved Photostability." Advanced Materials 31.23 (2019): e1901152.

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