Abstract
Development of transparent-conducting oxide (TCO) back contact for Cu(In,Ga)Se2 (CIGS) absorber is crucial for bifacial CIGS photovoltaics. However, inherent GaOx formation at the TCO/CIGS interface has hampered the photocarrier extraction. Here, by controlling the Na doping scheme, we show that the hole transporting properties at the indium-tin oxide (ITO)/CIGS back contact can be substantially improved, regardless of the GaOx formation. Na incorporation from the glass substrate during the GaOx forming phase created defective states at the interface, which allowed efficient hole extraction from CIGS, while post Na treatment after GaOx formation did not play such a role. Furthermore, we discovered that an almost GaOx-free interface could be made by reducing the underlying ITO film thickness, which revealed that ITO/CIGS junction is inherently Schottky. In the GaOx-free condition, post-Na treatment could eliminate the Schottky barrier and create ohmic junction due to generation of conducting paths at the interface, which is supported by our photoluminescence analysis.
| Original language | English |
|---|---|
| Pages (from-to) | 1635-1644 |
| Number of pages | 10 |
| Journal | Journal of Physical Chemistry C |
| Volume | 123 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2019 Jan 24 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
Cite this
Control of Structural and Electrical Properties of Indium Tin Oxide (ITO)/Cu(In,Ga)Se2 Interface for Transparent Back-Contact Applications. / Son, Yu Seung; Yu, Hyeonggeun; Park, Jong Keuk; Kim, Won Mok; Ahn, Seung Yeop; Choi, Wonjun; Kim, Donghwan; Jeong, Jeung Hyun.
In: Journal of Physical Chemistry C, Vol. 123, No. 3, 24.01.2019, p. 1635-1644.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Control of Structural and Electrical Properties of Indium Tin Oxide (ITO)/Cu(In,Ga)Se2 Interface for Transparent Back-Contact Applications
AU - Son, Yu Seung
AU - Yu, Hyeonggeun
AU - Park, Jong Keuk
AU - Kim, Won Mok
AU - Ahn, Seung Yeop
AU - Choi, Wonjun
AU - Kim, Donghwan
AU - Jeong, Jeung Hyun
PY - 2019/1/24
Y1 - 2019/1/24
N2 - Development of transparent-conducting oxide (TCO) back contact for Cu(In,Ga)Se2 (CIGS) absorber is crucial for bifacial CIGS photovoltaics. However, inherent GaOx formation at the TCO/CIGS interface has hampered the photocarrier extraction. Here, by controlling the Na doping scheme, we show that the hole transporting properties at the indium-tin oxide (ITO)/CIGS back contact can be substantially improved, regardless of the GaOx formation. Na incorporation from the glass substrate during the GaOx forming phase created defective states at the interface, which allowed efficient hole extraction from CIGS, while post Na treatment after GaOx formation did not play such a role. Furthermore, we discovered that an almost GaOx-free interface could be made by reducing the underlying ITO film thickness, which revealed that ITO/CIGS junction is inherently Schottky. In the GaOx-free condition, post-Na treatment could eliminate the Schottky barrier and create ohmic junction due to generation of conducting paths at the interface, which is supported by our photoluminescence analysis.
AB - Development of transparent-conducting oxide (TCO) back contact for Cu(In,Ga)Se2 (CIGS) absorber is crucial for bifacial CIGS photovoltaics. However, inherent GaOx formation at the TCO/CIGS interface has hampered the photocarrier extraction. Here, by controlling the Na doping scheme, we show that the hole transporting properties at the indium-tin oxide (ITO)/CIGS back contact can be substantially improved, regardless of the GaOx formation. Na incorporation from the glass substrate during the GaOx forming phase created defective states at the interface, which allowed efficient hole extraction from CIGS, while post Na treatment after GaOx formation did not play such a role. Furthermore, we discovered that an almost GaOx-free interface could be made by reducing the underlying ITO film thickness, which revealed that ITO/CIGS junction is inherently Schottky. In the GaOx-free condition, post-Na treatment could eliminate the Schottky barrier and create ohmic junction due to generation of conducting paths at the interface, which is supported by our photoluminescence analysis.
UR - http://www.scopus.com/inward/record.url?scp=85060023085&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85060023085&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.8b11149
DO - 10.1021/acs.jpcc.8b11149
M3 - Article
AN - SCOPUS:85060023085
VL - 123
SP - 1635
EP - 1644
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 3
ER -