Indirect excitation and luminescence activation mechanisms of rare-earth doped wide bandgap degenerated semiconductors and their impact on the host's optical and electrical properties

Acronym

P_RE-LUM

Consortium Coordinator

Guerra Torres, Jorge Andres

Start Date

June 11, 2021

End Date

June 10, 2024

Status

https://purl.org/pe-repo/concytec/estadoProyecto#concluido

Description

The present proposal aims to systematically study thermal activation and host-mediated rare-earth (RE) indirect excitation mechanisms in sputtered Indium Tin Oxide (ITO) and Aluminum doped Zinc Oxide (AZO) thin films embedded with Terbium (Tb) and Thulium (Tm) impurities. These are direct wide bandgap degenerated semiconductors that have the potential to combine low electrical resistivity and high visible optical transmittance, with light emission features, when doped with REs. There are only a few reports where a transparent conductive oxide has been doped with REs. In these cases, very little or no light emission was observed.1¿4 In addition, there is a lack of consensus on the excitation and activation mechanisms of RE-doped, wide-bandgap materials. Here, we develop new dispersion models to describe the absorption edge and complex refractive index considering excitonic effects, coupled to Drude, Lorentz and direct fundamental absorption processes. Our models will be experimentally tested and will serve as a platform to assess the RE indirect excitation mechanism via the formation of bound excitons to RE clusters in these materials. We expect to make the latter excitation mechanism evident by inducing the thermal quenching of the RE-related luminescence in a temperature range in which excitons cannot exist, thus determining the excitonic binding energy for RE clusters with different sizes. The project is aligned with the Dielectric Materials and Films ONR program and we believe it substantially contributes to the U.S. objective of mitigating potential supply disruption and lack of innovation in the area of RE materials. We aim to conduct fundamental research in order to develop novel RE-doped, wide bandgap semiconductor materials with optoelectronic properties that are suitable for applications in the naval, military and defense fields, renewable energies, light emitting and sensing devices, gas sensors and advanced optoelectronics.

Keywords

Semiconductores dopados

;

Tierras raras

;

Luminiscencia

;

Propiedades optoelectrónicas

Área de conocimiento

Natural sciences

Campo OCDE

https://purl.org/pe-repo/ocde/ford#1.03.06