Low-Temperature Photoluminescence of Nanostructured ZnO Crystal Synthesized by Pulsed-Laser Ablation

Abstract

The optical properties of ZnO nanorods and nanowires grown by our newly developed nanoparticle-assisted pulsed-laser deposition (NAPLD) technique were studied by photoluminescence (PL) spectroscopy. This NAPLD technique, which does not require a catalyst for crystal growth, is expected to synthesize high-quality nanostructured ZnO crystals. The green luminescence (GL) band and ultraviolet luminescence (UVL) observed at low temperature were investigated for these crystals. The UVL band consists of several sharp emission lines due to free excitons, donor-bound excitons, donor-acceptor pair (DAP) transitions, and their longitudinal-optical (LO) phonon replicas. The free-exciton binding energy was estimated to be 59 meV and the band gap of these ZnO crystals was determined to be 3.435 eV at 10 K. The temperature variation for the energy positions of free-exciton emission was fitted by the Manoogian-Woolley equation and the Debye temperature was estimated to be 505 K. The low-temperature PL investigation of our nanostructured ZnO crystals that were easily synthesized by our newly developed NAPLD technique demonstrated their excellent crystallinity.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…The energy separation between these phonon replicas, as labeled in Fig. 40(b), matched well with the reported phonon energies in ZnO crystals [1,[360][361][362].…”

A study on structural formation and optical property of wide band-gap Be0.2Zn0.8O layers grown by RF magnetron co-sputtering system

“…This emission was attributed to a free exciton (E x ) transition from the localized level below the conduction band to the valence band. Thus, the E x emission of ZnO measured at 10 K by Sakai et al [13] was 3.376 eV. In fact, this near band energy of BeZnO is very large in comparison with that on ZnO [13].…”

“…Thus, the E x emission of ZnO measured at 10 K by Sakai et al [13] was 3.376 eV. In fact, this near band energy of BeZnO is very large in comparison with that on ZnO [13]. Therefore, this means that the ternary BeZnO compound is a material having wide band-gap energy.…”

Low-temperature photoluminescence of phosphorous-doped ZnO nanowires synthesized by nanoparticle-assisted pulsed-laser deposition

“…We have successfully grown nondoped ZnO nanowires by a newly developed nanoparticle-assisted pulsedlaser deposition (NAPLD) technique that does not require the use of any catalyst [6][7][8][9]. And we also found and demonstrated that these crystals had good crystallinity from low-temperature photoluminescence (PL) measurements [10,11].…”