TY - JOUR
T1 - Influence of La3+ doping on the band gap mediated ultraviolet photoconductivity of spray pyrolyzed ZnO thin films
AU - Srivathsa, Manu
AU - Rajendra, B. V.
N1 - Funding Information:
The authors grateful to. 1. Manipal Academy of Higher Education (MAHE) for providing a research facility. 2. UGC-DAE CSR Mumbai Centre for sanctioning collaborative research project (UDCSR/MUM/AO/CRS-M-315/2020/813). 3. RRCAT Indore center for providing XPS facility. 4. Dr. Sudha D Kamath, Department of Physics, MIT Manipal for providing the photoluminescence facility. 5. Dr. Gowrish Rao K, Department of Physics, MIT Manipal for providing the photo-response facility.
Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2024/1
Y1 - 2024/1
N2 - The present work focuses on the effect of bandgap engineering on the photo sensing application of Lanthanum (La3+) doped ZnO thin films deposited on glass substrates using spray pyrolysis technique. The × ray diffraction of films showed the polycrystalline nature having hexagonal wurtzite structure with preferred orientation of (1 0 1) plane. The Zn0.94La0.06O films exhibited highest crystallinity of ∼23.7 nm. The strain and dislocation density decreased till 6 at% La3+ doping and increased for higher doping concentrations. The change in the fibrous structure to grain like morphology with the addition La was noticed at higher doping concentration. The composition analysis confirmed the presence of elements and its state of Zn, O and La in the deposited films. The Zn0.94La0.06O film showed visible region transparency above 90 % and band gap of ∼3.27 eV. The near band edge emission (NBE) and deep level emission (DLE) were noticed in all the films. The defects decreased with the La addition due to the proper incorporation of La3+ in ZnO lattice. The pure ZnO films showed the maximum oxygen related defects (∼58.8 %) and Zn0.94La0.06O films showed lesser defects (∼13 %). The electron carrier concentration ∼8.48 × 1016 cm−3, mobility ∼49.6 cm2/V and the resistivity ∼2.52 × 102 Ω cm were noticed in Zn0.94La0.06O films. The photocurrent of Zn1-xLaxO increased till x = 6 at% under the ultraviolet light illumination because of the incident photon energy was higher than the band gap of the film. The Zn0.94La0.06O films showed faster response time and maximum photocurrent at 380 nm. Hence the Zn0.94La0.06O films may be employed in the development of possible optoelectronic devices.
AB - The present work focuses on the effect of bandgap engineering on the photo sensing application of Lanthanum (La3+) doped ZnO thin films deposited on glass substrates using spray pyrolysis technique. The × ray diffraction of films showed the polycrystalline nature having hexagonal wurtzite structure with preferred orientation of (1 0 1) plane. The Zn0.94La0.06O films exhibited highest crystallinity of ∼23.7 nm. The strain and dislocation density decreased till 6 at% La3+ doping and increased for higher doping concentrations. The change in the fibrous structure to grain like morphology with the addition La was noticed at higher doping concentration. The composition analysis confirmed the presence of elements and its state of Zn, O and La in the deposited films. The Zn0.94La0.06O film showed visible region transparency above 90 % and band gap of ∼3.27 eV. The near band edge emission (NBE) and deep level emission (DLE) were noticed in all the films. The defects decreased with the La addition due to the proper incorporation of La3+ in ZnO lattice. The pure ZnO films showed the maximum oxygen related defects (∼58.8 %) and Zn0.94La0.06O films showed lesser defects (∼13 %). The electron carrier concentration ∼8.48 × 1016 cm−3, mobility ∼49.6 cm2/V and the resistivity ∼2.52 × 102 Ω cm were noticed in Zn0.94La0.06O films. The photocurrent of Zn1-xLaxO increased till x = 6 at% under the ultraviolet light illumination because of the incident photon energy was higher than the band gap of the film. The Zn0.94La0.06O films showed faster response time and maximum photocurrent at 380 nm. Hence the Zn0.94La0.06O films may be employed in the development of possible optoelectronic devices.
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U2 - 10.1016/j.optlastec.2023.109939
DO - 10.1016/j.optlastec.2023.109939
M3 - Article
AN - SCOPUS:85171620840
SN - 0030-3992
VL - 168
JO - Optics and Laser Technology
JF - Optics and Laser Technology
M1 - 109939
ER -