Investigations of RT transmission and photoluminescence (PL)
spectra were performed using the Solar Spectrofluorimetr CM
2203 with two double monochromators, the Xe lamp as excitation
source and the Hamamatsu photomultiplier (PMT). LT magneto-PL
investigations were performed using a Spectromag 6000 split coil
superconductive magnet of Oxford Instruments, He–Cd laser PLASMA
model HCCL-15UM, a double monochromator equipped with
Hamamatsu S7035 CCD camera and Hamamatsu photon counting
system with R2531 PMT and FAST ComTec 7887 card. CL and
SEM measurements were performed using Scanning Electron
Microscope Hitachi SU-70 equipped with a GATAN MonoCL
System.