Projects per year
Abstract
Tin sulfide solar cells show relatively poor efficiencies despite attractive photovoltaic properties, and there is difficulty in identifying separate phases, which are also known to form during Cu2ZnSnS4 depositions. We present X-ray photoemission spectroscopy (XPS) and inverse photoemission spectroscopy measurements of single crystal SnS, SnS2, and Sn2S3, with electronic-structure calculations from density functional theory (DFT). Differences in the XPS spectra of the three phases, including a large 0.9 eV shift between the 3d5/2 peak for SnS and SnS2, make this technique useful when identifying phase-pure or mixed-phase systems. Comparison of the valence band spectra from XPS and DFT reveals extra states at the top of the valence bands of SnS and Sn2S3, arising from the hybridization of lone pair electrons in Sn(II), which are not present for Sn(IV), as found in SnS2. This results in relatively low ionization potentials for SnS (4.71 eV) and Sn2S3 (4.66 eV), giving a more comprehensive explanation as to the origin of the poor efficiencies. We also demonstrate, by means of a band alignment, the large band offsets of SnS and Sn2S3 from other photovoltaic materials and highlight the detrimental effect on cell performance of secondary tin sulfide phase formation in SnS and CZTS films.
Original language | English |
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Pages (from-to) | 3718–3726 |
Number of pages | 8 |
Journal | Chemistry of Materials |
Volume | 28 |
Issue number | 11 |
Early online date | 9 May 2016 |
DOIs | |
Publication status | Published - 14 Jun 2016 |
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Dive into the research topics of 'Band alignments, valence bands, and core levels in the tin sulfides SnS, SnS2, and Sn2S3: Experiment and Theory'. Together they form a unique fingerprint.Projects
- 1 Finished
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Applying Long-Lived Metastable States in Switchable Functionality via Kinetic Control of Molecular Assembly
Raithby, P. (PI), Burrows, A. (CoI), Lewis, D. (CoI), Marken, F. (CoI), Parker, S. (CoI), Walsh, A. (CoI) & Wilson, C. (CoI)
Engineering and Physical Sciences Research Council
1/11/12 → 30/04/18
Project: Research council
Equipment
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Balena High Performance Computing (HPC) System
Facility/equipment: Equipment
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High Performance Computing (HPC) Facility
Chapman, S. (Manager)
University of BathFacility/equipment: Facility