Band Gap Enhancement and Temperature Dependent PL in Sol-gel Synthesized Ce Doped ZnO Nanoparticles

Authors Ashok Kumawat , Saikat Chattopadhyay , Nilanjan Halder , Kamakhya Prakash Misra

Department of Physics, School of Basic Sciences, Manipal University Jaipur, 303007 Rajasthan, India

Issue Volume 13, Year 2021, Number 2
Dates Received 10 January 2021; revised manuscript received 25 March 2021; published online 09 April 2021
Citation Ashok Kumawat, Saikat Chattopadhyay, et al., J. Nano- Electron. Phys. 13 No 2, 02001 (2021)
PACS Number(s) 78.55.Kz, 42.70.Qs
Keywords Sol-gel method (4) , CeZnO, Band gap enhancement, Temperature dependent PL, Optoelectronics applications.

Sol-gel synthesis route was adopted to prepare undoped and 2 at. % Ce doped ZnO (CZO) nanoparti-cles (NPs). Distinct characteristic absorption peaks at 520 and 524 cm – 1 are seen in FTIR spectra of NPs, which generally correspond to Zn–O stretching mode. This confirmed the formation of ZnO in the samples. Other peaks at 628 and 631 cm – 1 were also observed corresponding to Zn–O–Zn antisymmetric vibrations. UV-Vis transmission spectra revealed absorption dips at 370 and 364 nm respectively for undoped ZnO and CZO NPs and the corresponding band gap values were estimated to be 3.34 and 3.41 eV. The photo-luminescence (PL) emission spectra of undoped ZnO NPs had one major peak at 391 nm (UV) along with feeble visible peaks at 467, 480 and 492 nm. The UV peak observes a continuous rise in intensity with re-duction in temperature ranging from 50 ºC to – 10 ºC. The UV peak also blue-shifted slightly with tempera-ture lowering. The temperature dependent PL spectra of CZO NPs too had similar peaks but a very feeble change in the intensity with temperature was noticed and the blue-shift of the UV peak occurred at nega-tive temperature. The temperature dependent PL properties and band gap enhancement in CZO NPs may have potential applications in optoelectronics.

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