“…In particular, they are implemented in the engineering of solar cells [ 1 , 2 , 3 , 4 ], optoelectronics, photonics, gas- [ 5 ] and biosensors [ 6 ], and photocatalysis [ 7 ]. Another important application of the ZnO nanostructures is radiation detectors (scintillators) [ 8 , 9 ]. Moreover, they have the strong potential for ultrafast detection in time-of-flight positron emission tomography [ 10 ] due to ultraviolet (UV) exciton emission with the maximum at about 380 nm (3.26 eV) [ 11 , 12 , 13 , 14 , 15 ].…”