Photoluminescence studies in ZnO samples

Photoluminescence and damage recovery studies in Fe-implanted ZnO single crystals

“…Similar emission lines were previously reported. 1,8,9 The transitions are currently assigned to D 0 X ͑and A 0 X) complexes, TES, and DAP recombinations. 1,8,9 After implantation and annealing procedures, the NBE PL is mainly dominated by the 3.36 eV emission, with minor lines at 3.309 and 3.239 eV also observed for the sample annealed in air.…”

“…7 Typically, with intrinsic excitation, the low-temperature photoluminescence ͑PL͒ spectra of undoped ZnO single crystals are characterized by complex near-band-edge ͑NBE͒ spectra dominated by the recombination of free excitons ͑FXA͒, rotor states (EϾ3.37 eV), and neutral donor/ acceptor bound-exciton complexes (D 0 X,A 0 X) near 3.36 eV followed by 72.8-meV LO phonon replicas. 1,8,9 At lower energies, 29.9 meV below the exciton complexes, two-electron satellite ͑TES͒ recombination is observed. 1,8,9 Donoracceptor pair ͑DAP͒ recombination at 3.22 eV followed by LO phonon replicas is usually present.…”

“…1,8,9 At lower energies, 29.9 meV below the exciton complexes, two-electron satellite ͑TES͒ recombination is observed. 1,8,9 Donoracceptor pair ͑DAP͒ recombination at 3.22 eV followed by LO phonon replicas is usually present. 1,8,9 Besides these structured NBE emissions, deep-level structureless emissions are commonly observed in undoped ZnO single crystals, 10,11 powder samples, 12,13 thin films, 14,15 and nanocrystalline particles.…”

“…1,8,9 Donoracceptor pair ͑DAP͒ recombination at 3.22 eV followed by LO phonon replicas is usually present. 1,8,9 Besides these structured NBE emissions, deep-level structureless emissions are commonly observed in undoped ZnO single crystals, 10,11 powder samples, 12,13 thin films, 14,15 and nanocrystalline particles. 16 The centers responsible for the unstructured emission bands in the green, yellow, and red spectral regions are usually assumed to be due to different native defects in ZnO, such as oxygen vacancy (V O ), zinc vacancy (V Zn ), interstitial zinc, interstitial oxygen, and antisite defect (O Zn ).…”

Effect of temperature on isotopic mass dependence of excitonic band gaps in semiconductors: ZnO

“…14 Previously, the temperature dependence of its A, B, and C excitonic band gaps, associated with the lowest conduction band and the top three valence bands at the center of the Brillouin zone, has been studied from 4.2 to 300 K employing reflectivity, 15 photoluminescence ͑PL͒, [15][16][17] and photoluminescence excitation spectroscopy ͑PLE͒. 18 In addition, the isotopic dependence of the ZnO band gaps has been investigated at low temperature by wavelength-modulated reflectivity 19,20 and PL.…”