The effect of adding terbium to indium tin oxide (ITO) thin films on the electrical, optical and light emission properties was investigated. The films were prepared by radio frequency dual magnetron sputtering, maintaining a high optical transmittance in the ultraviolet and visible spectral regions, and a low electrical resistivity ranging from 5×10-3 ω ...cm to 0.3 ω ...cm . Terbium-related luminescence is achieved after annealing at 470 C in air at atmospheric pressure. Electrical resistivity and optical transmittance were measured after each annealing step to evaluate the compromise between the achieved light emission intensity, electrical and optical properties. Additionally, temperature dependence of Tb-related luminescence quenching was assessed by temperature-dependent photoluminescence measurements, from 83 to 533 K, under non-resonant excitation. Thermal quenching activation energies suggest an effective energy transfer mechanism from the ITO host to the rare-earth (RE) ions. This indirect excitation mechanism was modeled using a spherical potential-well and a tight-binding one-band approximation approaches, describing a short-range charge trapping process and subsequent formation of bound excitons to RE ion clusters.
Bibliographical noteFunding Information:
This research was funded by the Peruvian National Fund for Scientific, Technological Development and Technological Innovation (FONDECYT), Grant No. 179-2020-FONDECYT, and was supported by the Research Management Office (DGI) of the Pontificia Universidad Católica del Perú (PUCP), Grant No. 2019-3-0041/702 and the Office of Naval Research, Grant No. N62909-21-1-2034. The authors acknowledge the CITE and CAM laboratories of the PUCP for supporting the development of this work. Further support for travel expenses has been provided by the DAAD-CONCYTEC Grant Nos. 423-2019 and 57508544.
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- energy transfer
- optoelectronic properties
- rare-earth luminescence
- thin film
- transparent conductive oxide