1. Department of Materials Science and Engineering, and Optoelectronics Convergence Research Center, Chonnam National University, Gwangju 61186, Republic of Korea
2. Photovoltaics Laboratory, Korea Institute of Energy Research, 152 Gajeong-ro,
Yuseong-gu, Daejeon 34129, Republic of Korea
3. Department of Renewable Energy Engineering, Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea