Influence of Mo doping on the luminescence properties and defect states in ZnO nanorods. Comparison with ZnO:Mo thin films

NANOCON 2021 Conference Proeedings

Buryi

Sharma

et al. 2021

Plasma hydrogenation of hydrothermally grown ZnO nanorods was done at 13.56 MHz in inductively coupled plasma (ICP) with H2/Ar gas mixture. Plasma was monitored by optical emission spectroscopy (OES) and by measuring self-bias potential of the stainless-steel sample holder isolated from the ground by a capacitor. The ZnO surface chemical composition was studied by XPS. The exciton-related UV photoluminescence of ZnO nanorods and optical absorption increased significantly after plasma treatment and diminished after plasma oxidation. Increasing Ar in hydrogen plasma caused more negative self-bias, less efficient hydrogenation and lower exciton photoluminescence. We attribute changes of optical properties to changes of surface and related electronic states giving also rise to its black color visually.

Section: Resultsmentioning

confidence: 99%

Emergence of DARK ZnO Nanorods by Hydrogen Plasma Treatment

NANOCON 2021 Conference Proeedings

Buryi

Sharma

et al. 2021

“…The red emission bands (1.8-2 eV) related to VZn [5,6] were recently also observed in the hydrothermally grown ZnO nano-and microrods [7,8]. It is known that low-level Mo doping (below 1%) can positively affect the luminescence properties of ZnO (both defect-related and exciton luminescence) [7,8], whereas doping with 10 and 30% of Mo deteriorates them. Moreover, Mo has the tendency to couple with ZnO creating some new phase other than ZnO itself.…”

Section: Introductionmentioning

confidence: 89%

“…For example, the experimentally observed broad red bands ranging from 1 to 2 eV were related to zinc (VZn) or oxygen (VO) vacancies [5]. The red emission bands (1.8-2 eV) related to VZn [5,6] were recently also observed in the hydrothermally grown ZnO nano-and microrods [7,8]. It is known that low-level Mo doping (below 1%) can positively affect the luminescence properties of ZnO (both defect-related and exciton luminescence) [7,8], whereas doping with 10 and 30% of Mo deteriorates them.…”

Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

“…ZnO structure can also be characterized by the typical electron paramagnetic resonance (EPR) single-line signal observed at the g factor g ≈ 1.96 ascribed to the shallow Ga, Al, H donors (SD) [9][10][11][12], the Zn + + D complex, D = Ga, Al, H [8]. The influence of Mo on this shallow donor was studied earlier [6,8] in the ZnO:Mo(0.05, 0.25, 1%) and ZnO:Mo(10, 30%). However, there is no systematic investigation of the influence of Mo at the doping level within 2-25% on ZnO structure, morphology and creation of zinc-molybdenum complex oxides, luminescence and magnetic properties.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Transformation of ZnO-based structures under heavy Mo doping: defect states and luminescence

Buryi

NANOCON 2021 Conference Proeedings

Děcká

et al. 2021

Hydrothermally grown ZnO-based structures were heavily doped with Mo (various doping levels from 2 to 25%). Mo was found to strongly affect the structure and morphology of ZnO, resulting in a complex mixture of zinc oxide and molybdenum. Moreover, the transformation of material phases upon the increased Mo content was observed. ZnO phase was observed only at low Mo doping level (2 and 5%). This correlated very well to the changes in the luminescence and electron paramagnetic resonance signals.

Plasma Treatment of Ga‐Doped ZnO Nanorods

Míčová

Physica Status Solidi (a)

Artemenko

et al. 2022

A comparative study of structural, optical properties of plasma‐treated Ga‐doped ZnO nanorods (GZO NRs) prepared by hydrothermal growth is presented, which provides an economical technology for fast production. Annealing in air followed by plasma treatment has been found to be an effective way of purification of ZnO NRs. The plasma hydrogenation and oxidation are done at room temperature in an inductively coupled plasma (ICP) reactor. The properties of plasma‐treated GZO NRs are investigated using various characterization methods, such as scanning electron microscopy (SEM), Raman, Fourier transform infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), and electron paramagnetic resonance (EPR) spectroscopy. The SEM confirms the hexagonal shape of all GZO NRs. XPS reveals the presence of metallic Ga as well as Ga2O3 on GZO NRs surface. XRD has detected hexagonal (P63mc) ZnO phase in all samples with additional diffraction pattern in powder that has not been plasma treated. Plasma treatment does not affect the position of FTIR signals but changes the intensity of some absorption peaks. EPR shows a dominant signal with a g‐factor of 1.96. Plasma treatment of GZO samples affects its intensity.