1. Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, R.O.C.
2. Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, R.O.C.
3. Department of Applied Science, Chinese Naval Academy, Kaohsiung 813, Taiwan, R.O.C.
4. Department of Electronics Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, R.O.C.
5. Department of Electronics Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan, R.O.C.
6. Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, R.O.C.
7. SmartKem Ltd., Hexagon Tower Blackley, Manchester M9 8GQ, U.K.