Photoluminescence of hydrothermally epitaxied ZnO films

The modification of structural and optical properties of nano- and submicron ZnO powders by variation of solvothermal syntheses conditions

“…However, many different opinions about origin of visible PL emissions were presented in literature, and various types of defects, responsible for the same colored emission, were reported. In regard to the orange emission, some authors Greene et al 2003;Sim et al 2007;Shim et al 2003) mutually agree in the opinion that orange emission appears in oxygen-rich ZnO samples. The excess oxygen in ZnO samples usually places in interstitial position of crystal lattice The energies of the orange emission for all solvothermally synthesized ZnO powders are ranging from 2.02 to 2.07 eV (see Table 3).…”

Investigation of morphology and photoluminescence of hydrothermally grown ZnO nanorods on substrates pre-coated with ZnO nanoparticles

“…In hydrothermal growth, the visible defect emissions consists of orange and green components. Both components can present themselves simultaneously in the same sample [21]. Orange emission is typically related to interstitial oxygen while the assignment of green emission remains controversial as it has been attributed to various defects such as donor-acceptor pair, oxygen vacancy, anti-site oxygen, zinc interstitials and zinc vacancies [16].…”

“…This allows the interstitial zinc to diffuse into zinc vacancy sites and thus reduce the green emission intensity under various annealing conditions. The slight increase in green emission after annealing at 800 1C in nitrogen is attributed to removal of hydrogen defects as water molecules [21].…”

Role of OH− in the low temperature hydrothermal synthesis of ZnO nanorods

“…20 It is also reported that the different shape of the ZnO particles results from the charge type of zinc complexes in the solution with a pH of 6.7 or 11. 21 When the pH of the zinc nitrate solution was changed from 8.8 to 9.7, the diameter of ZnO increased from 50 to 170 nm, with an increase in length. 22 When the pH of zinc acetate solution was reduced from 6.8 to 5 by adding HCl and CH 3 COOH, the size of ZnO crystals decreased.…”