Journal article
Wide Band Gap Cu2SrSnS4 Solar Cells from Oxide Precursors
Department of Physics, Technical University of Denmark1
Surface Physics and Catalysis, Department of Physics, Technical University of Denmark2
Department of Photonics Engineering, Technical University of Denmark3
Nanofabrication, National Centre for Nano Fabrication and Characterization, Technical University of Denmark4
National Centre for Nano Fabrication and Characterization, Technical University of Denmark5
Department of Energy Conversion and Storage, Technical University of Denmark6
Silicon Microtechnology, Nanofabrication, National Centre for Nano Fabrication and Characterization, Technical University of Denmark7
Recent progress in the efficiency of Cu2ZnSnS4 (CZTS) solar cells has been relatively slow due to severe bulk band tailing issues that have proven difficult to resolve. Band tails in CZTS are caused by defect-related potential fluctuations, as diagnosed by the large shift between the CZTS band gap and its photoluminescence (PL) peak.
In this work, we demonstrate that the PL-band gap shift can be decreased roughly by a factor of 5 when Zn is replaced by the heavier cation Sr. The resulting Cu2ZnSnS4 compound is of considerable interest for photovoltaics due to its sharp band edges and suitable band gap (1.95–1.98 eV) for a top absorber in tandem cells.
Trigonal CSTS thin films are synthesized by sulfurization of strongly Cu-poor cosputtered Cu2ZnSnS4 precursors. The first functioning CSTS solar cells are demonstrated, even though the very high conduction band of CSTS implies that the typical CdS/ZnO electron contact of CZTS solar cells must be redesigned to avoid large voltage losses.
| Language: | English |
|---|---|
| Publisher: | American Chemical Society |
| Year: | 2019 |
| Pages: | 7340-7344 |
| ISSN: | 25740962 |
| Types: | Journal article |
| DOI: | 10.1021/acsaem.9b01322 |
| ORCIDs: | Crovetto, Andrea , Seger, Brian , Chorkendorff, Ib , Vesborg, Peter C. K. , Nielsen, Rasmus , Stamate, Eugen and Hansen, Ole |
