Luminescent spectroscopy and imaging of textured sprayed Er-doped ZnO films in the near ultraviolet and visible regions

Abstract

The textural dependence of the thermally sprayed Er-doped ZnO films on Er concentration is reported here. The [002] preferred growth orientation of hexagonal phase is obtained at the lower concentrations, while the [100] and [101] directions additionally raised from nearly 5at.% Er content onwards. The cathodoluminescent characteristics of the samples in the near ultraviolet (UV) and visible region depict a complete extinction of the visible emitted bands (λ=445, 526, and 665nm) at 1at.% Er content. Their deactivation below this concentration is explained by a compensation of oxygen defects in the material due to the oxygen-rich medium of the deposition bath. Their reactivation beyond this particular concentration is ascribed to the increase of the Er+3 ion shells whose internal radiative transitions lead to a recovering of these visible emitted bands. The radiative mechanism of the transitions from the (F9∕24) excited states to the (I15∕24) ground state, responsible for the λ=665nm emission, is predominant in that case. The respective normalized intensity of the violet (λ=445nm) and green (λ=526nm) emitted bands exhibits a maximal value for 3at.% Er content, reaching a stabilized regime from about 5at.% Er.

Photocatalytic degradation of endocrine disruptor Bisphenol-A in the presence of prepared CexZn1−xO nanocomposites under irradiation of sunlight

“…In this study, cerium (Ce) was chosen as the metal dopant as Ce 2+ ions create an impurity state below the conduction band (CB) edge of semiconductors (Bubendorff et al, 2006). CeO 2 has a band gap of about 3 eV and may be an ideal material for visible light-emitting phosphors in display, high-power laser, and light-emitting diode (Lang et al, 2010;Jung et al, 2012).…”

Photoluminescence of Er-doped ZnO nanoparticle films via direct and indirect excitation

“…[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] ZnO is a wide direct band-gap semiconductor with an oxide phase, which is applicable to the excitation of Er centers. 11 The Er-doped ZnO films have been fabricated using various techniques. 7-9 N-type doping of ZnO is very well developed and p-type doping is still difficult.…”

“…ZnO has a high electric conductivity, which is essential for the realization of actual current injection opto-electronic devices. [11][12][13][14][15][16][17][18] The advantage of e-beam evaporation is to achieve a uniform doping profile and to reach a high doping concentration that is not possible for ion implantation to achieve. 10 Other notable properties of ZnO include a large exciton binding energy (60 meV) and a large Zn-O bond strength.…”

Energy dissipation channels affecting photoluminescence from resonantly excited Er3+ ions doped in epitaxial ZnO host films

“…Up to now, PL from Er 3þ ions doped in various shapes of ZnO crystals have been reported, including visible [8][9][10][11][12][13] and infrared wavelength range. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] Despite extensive studies, how the crystal quality of ZnO hosts is correlated with emission intensities is still poorly understood.…”