Unraveling interface characteristics of Zn(O,S)/Cu(In,Ga)Se-2 at nanoscale: Enhanced hole transport by tuning band offsets
- 주제(키워드) Cu(InGa)Se-2 thin-film solar cells , Zn(O , S) buffer layer , Kelvin probe force microscopy (KPFM) , Micro-Raman scattering spectroscopy
- 주제(기타) Chemistry, Physical
- 주제(기타) Materials Science, Coatings & Films
- 주제(기타) Physics, Applied
- 주제(기타) Physics, Condensed Matter
- 설명문(일반) [Kim, Juran; Kim, Jayeong; Ko, Eunji; Park, Ha Kyung; Yoon, Seokhyun; Jo, William] Ewha Womans Univ, New & Renewable Energy Res Ctr NREC, Dept Phys, Seoul 03760, South Korea; [Cho, Dae-Hyung; Lee, Woo-Jung; Chung, Yong-Duck] Elect & Telecommun Inst ETRI, ICT Mat Res Grp, Daejeon 34129, South Korea; [Chung, Yong-Duck] Korea Univ Sci & Technol UST, Dept Adv Device Technol, Daejeon 34113, South Korea
- 등재 SCIE, SCOPUS
- 발행기관 ELSEVIER
- 발행년도 2020
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000168721
- 본문언어 영어
- Published As https://dx.doi.org/10.1016/j.apsusc.2019.144782
초록/요약
Environment-friendly Cu(In,Ga)Se-2 (CIGS) solar cells requires the replacement of Cd-containing buffers with non-toxic materials. Zn(O,S) buffers have been developed and yielded even better efficiency than CdS-buffered CIGS thin-film solar cells [23.35%, Ref. [6]]. In this work, we studied band offsets of Zn(O,S) and CIGS interfaces. The Cd-free buffer layers were deposited with 1.0%, 1.3%, and 1.6% oxygen (O-2) gas partial pressure during the deposition. Effects of the oxygen partial pressure on the structure and electronic properties of the devices were investigated by micro-Raman scattering spectroscopy and Kelvin probe force microscopy, respectively. We achieved depth-profiling of spatial work function mapping across the interface between the absorbers and the buffers. The best efficiency sample, grown using 1.3% of oxygen, showed 80 mV spike-like band offsets. We propose that the efficiency can be improved through tailoring of the band offsets at the interface as well as improving the absorber and the buffer materials.
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