Abstract
We investigated the surface properties of a Mo back contact for large-area thin-film solar modules with high efficiency and good adhesion between Mo and the absorber layer. It was determined that the appropriate surface properties of Mo would improve the efficiency from 10% to above 15.0±0.21% and narrow the efficiency distribution in large-area modules. The Mo back contact was annealed at various temperatures between room temperature and 230 °C in air to control the amount of sodium diffusing from the soda-lime glass substrate during selenization and sulfurization, and to improve the uniformity of the unit cell. Before the heat treatment, the amount of sodium in the patterned area of the unit cell was more than 10 times of that in the central area of the cell. The patterned region with higher Na content had smaller grains than those in the central area with less Na, resulting in many peel-offs and shunting paths. The difference in sodium content was reduced after heat treatment. The optimized surface oxide of the Mo back contact had a thickness of around 3-5 nm and consisted of the MoO3 phase. The grain boundary of Mo columnar structure near the surface consisted of the oxide layer.
| Original language | English |
|---|---|
| Pages (from-to) | 445-450 |
| Number of pages | 6 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 144 |
| DOIs | |
| Publication status | Published - 2016 Jan 1 |
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Keywords
- Abbreviations BZO boron-doped zinc oxide
- CBD chemical bath deposition
- CIGSS copper-indium-gallium-sulfur selenide, Cu(In,Ga)(Se,S)
- FF fill factor
- IR imaging infrared imaging
- LPCVD low-pressure chemical vapor deposition
- SEM scanning electron microscopy
- SIMS secondary ion mass spectroscopy
- TCO transparent conductive oxide
- TEM transmission electron microscopy
- XPS X-ray photoelectron spectroscopy
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
Cite this
The oxidation effect of a Mo back contact on Cu(In,Ga)(Se,S)2 thin-film solar modules. / Nam, Junggyu; Kang, Yoon Mook; Kim, Dongseop; Baek, Dohyun; Lee, Dongho; Yang, Jungyup.
In: Solar Energy Materials and Solar Cells, Vol. 144, 01.01.2016, p. 445-450.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The oxidation effect of a Mo back contact on Cu(In,Ga)(Se,S)2 thin-film solar modules
AU - Nam, Junggyu
AU - Kang, Yoon Mook
AU - Kim, Dongseop
AU - Baek, Dohyun
AU - Lee, Dongho
AU - Yang, Jungyup
PY - 2016/1/1
Y1 - 2016/1/1
N2 - We investigated the surface properties of a Mo back contact for large-area thin-film solar modules with high efficiency and good adhesion between Mo and the absorber layer. It was determined that the appropriate surface properties of Mo would improve the efficiency from 10% to above 15.0±0.21% and narrow the efficiency distribution in large-area modules. The Mo back contact was annealed at various temperatures between room temperature and 230 °C in air to control the amount of sodium diffusing from the soda-lime glass substrate during selenization and sulfurization, and to improve the uniformity of the unit cell. Before the heat treatment, the amount of sodium in the patterned area of the unit cell was more than 10 times of that in the central area of the cell. The patterned region with higher Na content had smaller grains than those in the central area with less Na, resulting in many peel-offs and shunting paths. The difference in sodium content was reduced after heat treatment. The optimized surface oxide of the Mo back contact had a thickness of around 3-5 nm and consisted of the MoO3 phase. The grain boundary of Mo columnar structure near the surface consisted of the oxide layer.
AB - We investigated the surface properties of a Mo back contact for large-area thin-film solar modules with high efficiency and good adhesion between Mo and the absorber layer. It was determined that the appropriate surface properties of Mo would improve the efficiency from 10% to above 15.0±0.21% and narrow the efficiency distribution in large-area modules. The Mo back contact was annealed at various temperatures between room temperature and 230 °C in air to control the amount of sodium diffusing from the soda-lime glass substrate during selenization and sulfurization, and to improve the uniformity of the unit cell. Before the heat treatment, the amount of sodium in the patterned area of the unit cell was more than 10 times of that in the central area of the cell. The patterned region with higher Na content had smaller grains than those in the central area with less Na, resulting in many peel-offs and shunting paths. The difference in sodium content was reduced after heat treatment. The optimized surface oxide of the Mo back contact had a thickness of around 3-5 nm and consisted of the MoO3 phase. The grain boundary of Mo columnar structure near the surface consisted of the oxide layer.
KW - Abbreviations BZO boron-doped zinc oxide
KW - CBD chemical bath deposition
KW - CIGSS copper-indium-gallium-sulfur selenide, Cu(In,Ga)(Se,S)
KW - FF fill factor
KW - IR imaging infrared imaging
KW - LPCVD low-pressure chemical vapor deposition
KW - SEM scanning electron microscopy
KW - SIMS secondary ion mass spectroscopy
KW - TCO transparent conductive oxide
KW - TEM transmission electron microscopy
KW - XPS X-ray photoelectron spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84944202708&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84944202708&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2015.09.035
DO - 10.1016/j.solmat.2015.09.035
M3 - Article
VL - 144
SP - 445
EP - 450
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
SN - 0927-0248
ER -