1. V.Ye. Lashkaryov Institute of Semiconductor Physics of NAS of Ukraine, 03028 Kyiv, Ukraine
2. State University of Telecommunications, 7 Solomenska str, 03680 Kyiv, Ukraine
3. Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, 518060 Shenzhen, People's Republic of China
4. Institute for Nuclear Research of NAS of Ukraine, 47 Prospect Nauky, 03028 Kyiv, Ukraine