* Corresponding authors

^a Konkuk University-Fraunhofer ISE Next Generation Solar Cell Research Center (KFnSC), Konkuk University, Seoul 143-701, Korea
E-mail: trapezium_9@naver.com, anhijuk@konkuk.ac.kr

^b Mechanical and Aerospace Engineering, University of California at San Diego, La Jolla, CA 92093, USA
E-mail: kyhwang@ucsd.edu, jin@ucsd.edu

^c Department of Electrical Engineering, Chonnam National University, Gwangju 500-757, Korea
E-mail: gom8812@hanmail.net

^d Department of Advanced Materials Chemistry, Korea University (Sejong Campus), Sejong 339-700, Korea
E-mail: sangok@korea.ac.kr, dwcho@korea.ac.kr

^e Department of Chemistry, Konkuk University, Seoul 143-701, Korea
E-mail: chanim@konkuk.ac.kr