Cation vacancies in the alloy compounds of Cu2ZnSn(S1-xSex)(4) and CuIn(S1-xSex)(2)
2013 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 535, 318-321 p.Article in journal (Refereed) Published
The present work analyzes theoretically the formation energy of the cation vacancies V-Cu, V-In, V-Zn, and V-Sn in Cu2ZnSn(S1-xSex)(4) and CuIn(S1-xSex)(2) alloy compounds. An atomistic first-principles study is carried out by employing a generalized gradient approximation and a hybrid functional approach within the density functional theory, using the supercell approach to model the alloy compositions x = 0.00, 0.25, 0.50, 0.75, and 1.00. We find that the Cu vacancy is the most dominant cation vacancy with the lowest formation energy Delta H-f. The formation energy of V-Cu is very similar in both types of alloy compounds, while the formation energy of V-In in CuIn(S1-xSex)(2) is roughly the average value of the formation energies of V-Zn and V-Sn in Cu2ZnSn(S1-xSex)(4). Moreover, we find that the vacancy formation energies are larger in the S-rich compounds compared with the corresponding vacancies in the Se-rich compounds. The results suggest that the concentration of especially V-Cu can, to some extent, be controlled by anion alloying.
Place, publisher, year, edition, pages
2013. Vol. 535, 318-321 p.
CuInS2, CuInSe2, Cu2ZnSnS4, Cu2ZnSnSe4, Solar cells, Vacancies, Formation energy, Density functional theory
IdentifiersURN: urn:nbn:se:kth:diva-124465DOI: 10.1016/j.tsf.2012.11.063ISI: 000318973600071ScopusID: 2-s2.0-84878168820OAI: oai:DiVA.org:kth-124465DiVA: diva2:636150
Symposium B on Thin Film Chalcogenide Photovoltaic Materials of the 11th E-MRS Spring Meetings, MAY, 2012, Strasbourg, FRANCE
QC 201307092013-07-092013-07-052013-07-09Bibliographically approved