Optical properties of Cu2ZnSn(SxSe1-x)4 solar absorbers: Spectroscopic ellipsometry and ab initio calculations
2017 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 110, no 2, 021905Article in journal (Refereed) Published
Dielectric functions of Cu2ZnSn(SxSe1-x)4 thin film absorbers with varied x were determined by spectroscopic ellipsometry and ab initio calculations. From the combination of experimental and theoretical studies, the fundamental interband transition energy E0 (∼1-1.5 eV) and the next following transition energy E1 (∼2-3 eV) were identified and found to blue-shift with increasing sulfur anion content, while keeping the energy separation E1−E0 almost constant, ∼1.4 eV from experiments, and 1 eV from theory. In addition, the average dielectric responses were found to decrease with sulfur anion content from both theoretical and experimental results. The Tauc optical bandgap value Eg determined on samples prepared on Mo and soda lime glass substrate showed a positive linear relationship between x and bandgap Eg. The bandgap bowing factor determined from the theoretical data is 0.09 eV.
Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2017. Vol. 110, no 2, 021905
Calculations, Copper, Ellipsometry, Energy gap, Optical properties, Semiconducting selenium compounds, Spectroscopic ellipsometry, Substrates, Sulfur, Ab initio calculations, Dielectric functions, Dielectric response, Energy separations, Interband transition energies, Linear relationships, Soda lime glass substrate, Thin-film absorbers, Solar absorbers
IdentifiersURN: urn:nbn:se:kth:diva-202228DOI: 10.1063/1.4973353ISI: 000392835300025ScopusID: 2-s2.0-85009359176OAI: oai:DiVA.org:kth-202228DiVA: diva2:1082944
Correspondence Address: Li, S.-Y.; Ångström Solar Center, Solid State Electronics, Uppsala UniversitySweden; email: firstname.lastname@example.org. QC 201703202017-03-202017-03-202017-03-20Bibliographically approved