Optimization of ALD-(Zn,Mg)O buffer layers and (Zn,Mg)O/Cu(In,Ga)Se-2 interfaces for thin film solar cells
2007 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 15, 6024-6027 p.Article in journal (Refereed) Published
(Zn,Mg)O films, fabricated by atomic layer deposition, ALD, are investigated as buffer layers in Cu(In,Ga)Se2-based thin film solar cells. Optimization of the buffer layer is performed in terms of thickness, deposition temperature and composition. High efficiency devices are obtained for deposition at 105–135 °C, whereas losses in open circuit voltage are observed at higher deposition temperatures. The optimal compositional region for (Zn,Mg)O buffer layers in this study is for Mg/(Zn + Mg) contents of about 0.1–0.2, giving band gap values of 3.5–3.7 eV. These devices appear insensitive to thickness variations between 80 and 600 nm. Efficiencies of up to 16.2% are obtained for completely Cd- and S-free devices with (Zn,Mg)O buffer layers deposited with 1000 cycles at 120 °C and having a band gap of 3.6 eV.
Place, publisher, year, edition, pages
2007. Vol. 515, no 15, 6024-6027 p.
(Zn, Mg)O, Buffer layer, Cu(In, Ga)Se2, Solar cells
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-10910DOI: 10.1016/j.tsf.2006.12.047ISI: 000246831600059OAI: oai:DiVA.org:uu-10910DiVA: diva2:38678