MRS Meetings and Events


EN06.02.07 2023 MRS Fall Meeting

Valence Alternation in Quasi-One-Dimensional Antimony Selenide

When and Where

Nov 27, 2023
4:30pm - 4:45pm

Hynes, Level 3, Room 306



Xinwei Wang1,Seán Kavanagh1,2,Aron Walsh1,3

Imperial College London1,University College London2,Ewha Womans University3


Xinwei Wang1,Seán Kavanagh1,2,Aron Walsh1,3

Imperial College London1,University College London2,Ewha Womans University3
Antimony selenide (Sb<sub>2</sub>Se<sub>3</sub>) has emerged as an earth-abundant and environmental-friendly alternative among thin-film photovoltaic light absorbers due to its promising optoelectronic properties. A distinguishing feature of Sb<sub>2</sub>Se<sub>3</sub> is its anisotropic crystal structure, which is composed of quasi-one-dimensional (1D) [Sb<sub>4</sub>Se<sub>6</sub>]<i><sub>n</sub></i> ribbons. However, the current record conversion efficiency of Sb<sub>2</sub>Se<sub>3</sub> (~ 10%)<sup>[1]</sup> is far from optimal. It has been reported that orientation control of Sb<sub>2</sub>Se<sub>3</sub> films is important to achieve high device performance<sup> [2]</sup>, but the underlying physics remains unclear.<br/><br/>In this talk, I will present our most recent work<sup>[3-5]</sup> investigating reasons that affect the conversion efficiency in Sb<sub>2</sub>Se<sub>3</sub> based on first-principles calculations. I will first introduce the anisotropy in bulk Sb<sub>2</sub>Se<sub>3</sub> structure and the resulting impacts on structural, electronic and optical properties. Then I will present results on the unusual defect physics. Multi-electron negative-<i>U</i> transitions between defect charge states can be understood from valence alternation enabled by large local structural rearrangements. Finally, I will discuss potential strategies to optimize the performance of Sb<sub>2</sub>Se<sub>3</sub>-based photovoltaics.<br/><br/><b>References</b><br/>[1] Zhao Y, Wang S, Li C, et al. <i>Energy & Environmental Science</i>, 2022, 15(12): 5118-5128.<br/>[2] Zhou Y, Wang L, Chen S, et al. <i>Nature Photonics</i>, 2015, 9(6): 409-415.<br/>[3] Wang X, Li Z, Kavanagh S R, et al. <i>Physical Chemistry Chemical Physics</i>, 2022, 24(12): 7195-7202.<br/>[4] Wang X, Ganose A M, Kavanagh S R & Walsh A. <i>ACS Energy Letters</i>, 2022, 7(9): 2954-2960.<br/>[5] Wang X, Kavanagh S R, Scanlon D O & Walsh A<i>. arXiv preprint:</i>2302.04901, 2023.

Symposium Organizers

Aron Huckaba, University of Kentucky
Cecilia Mattevi, Imperial College London
Elisa Riedo, New York University
Christopher Sutton, University of South Carolina

Publishing Alliance

MRS publishes with Springer Nature