1. Instituto Politécnico Nacional—ESFM, Av. IPN, México City 07738, Mexico
2. Instituto Politécnico Nacional—UPIITA, Av. IPN, México City 07320, Mexico
3. V. Lashkaryov Institute of Semiconductor Physics at NASU, 45 Pr. Nauky, Kyiv 03028, Ukraine
4. Physics Department, National University “Kyiv-Mohyla Academy,” 2 Skovorody str., Kyiv 04170, Ukraine
5. CIMAP/UMR CNRS/CEA/ENSICAEN/UNICAEN, Bd. Marechal Juin, 4050 Caen Cedex 4, France