Abstract
The electrical properties of Cu(In,Ga)Se2/Mo junctions were characterized with respect of MoSe2 orientation and Na doping level using an inverse transmission line method, in which the Cu(In,Ga)Se2 (CIGS)/Mo contact resistance could be measured separately from the CIGS film sheet resistance. The MoSe2 orientation was controlled by varying the Mo surface density, with the c-axis parallel and normal orientations favored on Mo surfaces of lower and higher density, respectively. The effect of Na doping was compared by using samples with and without a SiOx film on sodalime glass. The conversion of the MoSe2 orientation from c-axis normal to parallel produced a twofold reduction in CIGS/Mo contact resistance. Measurements of the contact resistances as a function of temperature showed that the difference in CIGS/Mo contact resistance between the samples with different MoSe2 orientations was due to different barrier heights at the back contact. Comparison between Na-doped and Na-reduced samples revealed that the contact resistance for the Na-reduced system was four times of that of the doped sample, which showed more pronounced Schottky-junction behavior at lower temperature, indicating that Na doping effectively reduced the barrier height at the back contact.
Original language | English |
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Pages (from-to) | 90-96 |
Number of pages | 7 |
Journal | Progress in Photovoltaics: Research and Applications |
Volume | 22 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2014 Jan |
Keywords
- CIGS thin-film solar cells
- CIGS/Mo contact resistance
- MoSe orientation
- Na doping
- inverse transmission line method
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Condensed Matter Physics
- Electrical and Electronic Engineering