Title: Stabilized wide bandgap perovskite solar cells by tin substitution

Abstract

Wide bandgap MAPb(I_1-yBr_y)₃ perovskites show promising potential for application in tandem solar cells. However, unstable photovoltaic performance caused by phase segregation has been observed under illumination when y is above 0.2. Herein, we successfully demonstrate stabilization of the I/Br phase by partially replacing Pb²⁺ with Sn²⁺ and verify this stabilization with X-ray diffractometry and transient absorption spectroscopy. The resulting MAPb_0.75Sn_0.25(I_1-yBr_y)₃ perovskite solar cells show stable photovoltaic performance under continuous illumination. Among these cells, the one based on MAPb_0.75Sn_0.25(I_0.4Br_0.6)₃ perovskite shows the highest efficiency of 12.59% with a bandgap of 1.73 eV, which make it a promising wide bandgap candidate for application in tandem solar cells. The engineering of internal bonding environment by partial Sn substitution is believed to be the main reason for making MAPb_0.75Sn_0.25(I_1-yBr_y)₃ perovskite less vulnerable to phase segregation during the photostriction under illumination. Furthermore, this study establishes composition engineering of the metal site as a promising strategy to impart phase stability in hybrid perovskites under illumination.

Authors:

Yang, Zhibin ^[1]; Rajagopal, Adharsh ^[1]; Jo, Sae Byeok ^[1]; Chueh, Chu -Chen ^[1]; Williams, Spencer ^[1]; Huang, Chun -Chih ^[1]; Katahara, John K. ^[1]; Hillhouse, Hugh W. ^[1]; Jen, Alex K. -Y. ^[1]

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+ Show Author Affiliations

1. Univ. of Washington, Seattle, WA (United States)

Publication Date:

Wed Nov 16 00:00:00 EST 2016

Research Org.:

Univ. of Washington, Seattle, WA (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE)

Contributing Org.:

This work was supported by the National Science Foundation (DMR-1608279), the Office of Naval Research (N00014-14-1- 0246), the Asian Office of Aerospace R&D (FA2386-15-1- 4106), and the Department of Energy SunShot (DE-EE 0006710). A.-K.-Y.J. thanks the Boeing-Johnson Foundation for financial support. Z.Y. acknowledges the financial support from the State of Washington through the University of Washington Clean Energy Institute. The authors also thank Francis Lin and Ting Zhao for material synthesis and Liam Bradshaw for assistance in XRD setup.

OSTI Identifier:

1343605

Report Number(s):

DOE-UW-Jen-31
Journal ID: ISSN 1530-6984

Grant/Contract Number:  

EE0006710

Resource Type:

Accepted Manuscript

Journal Name:

Nano Letters

Additional Journal Information:

Journal Volume: 16; Journal Issue: 12; Journal ID: ISSN 1530-6984

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

14 SOLAR ENERGY; large bandgap; photo stability; phase segregation; Sn substitution