Analysis of Er3+ incorporation in SnO2 by optical investigation

Abstract

Er 3+ emission in the wide bandgap matrix SnO 2 is observed either through a direct Er ion excitation process as well as by an indirect process, through energy transfer in samples codoped with Yb 3+ ions. Electron-hole generation in the tin dioxide matrix is also used to promote rare-earth ion excitation. Photoluminescence spectra as function of temperature indicate a slight decrease in the emission intensity with temperature increase, yielding low activation energy, about 3.8meV, since the emission even at room temperature is rather considerable.

Structural, Optical and Photoluminescence Study of Nanocrystalline SnO2 Thin Films Deposited by Spray Pyrolysis

“…The advancement in nanostructured oxides has attracted new interest in exploiting these materials as components for nano scale light emitting devices (He et al 2006). Besides other material properties, photoluminescence (PL) properties of SnO 2 can be manipulated by varying the size, defects such as tin interstitials or oxygen vacancies, which act as radiative centres in luminescence process (Jeong et al 2003;Morais et al 2006). Thin films of SnO 2 can be prepared by many techniques, such as chemical vapour deposition, sputtering, sol-gel spin coating, reactive evaporation, pulsed laser ablation, screen printing technique, spray pyrolysis, etc.…”

Visible emission from Er-doped SnO2 thin films deposited by sol-gel

“…Generation of electron-hole pairs from the SnO 2 matrix can be provided with excitation below 350 nm, which is about the wavelength of band gap energy (3.5 eV) of SnO 2 . Nonradiative transitions may occur between 4 F 7/2 → 4 I 13/2 and 2 H 11/2 → 4 I 13/2 levels [21]. Indirect excitation can be obtained with the Yb 3+ 2 F 7/2 → 2 F 5/2 transition (980nm), in codoped samples, since this transition has energy coincident with Er 3+ 4 I 11/2 → 4 I 15/2 transition.…”