1. Department of Materials and Manufacturing Engineering, Hanbat National University, Daejeon 34158, Republic of Korea
2. Department of Materials Science and Engineering, Hanbat National University, Daejeon 34158, Republic of Korea
3. Department of Chemical and Biological Engineering, and Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08544, United States
4. Photovoltaics Research Department, Korea Institute of Energy Research (KIER), Daejeon 34129, Republic of Korea
5. Renewable Energy Engineering, University of Science and Technology (UST), Daejeon 34113, Republic of Korea