Optical properties of ThO₂-based nanoparticles

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• 作者：F.J. Pereira^a ; M.A. Castro^a ; M.D. Vá ; zquez^b ; L. Debá ; n^b ; A.J. Aller^a ; ^{aj.aller@unileon.es}
• 关键词：Band gap ; Thoria (ThO2) nanoparticles ; Arsenic doping ; Cysteine capping ; UV&ndash ; vis absorption spectra ; Photoluminescence spectra
• 刊名：Journal of Luminescence
• 出版年：2017
• 出版时间：April 2017
• 年：2017
• 卷：184
• 期：Complete
• 页码：169-178
• 全文大小：2632 K
• 卷排序：184

文摘

Thoria nanomaterials show great interest in different fields other than nuclear technology. In this work, optical characteristics of four types of thoria-based nanoparticles were evaluated. The ultraviolet-visible (UV–vis) absorption spectrum of the pure (undoped/uncapped) thoria nanoparticles was characterised by an intense peak at 222 nm, while the doped/capped thoria nanoparticles shown maximum absorption peaks at both 195/200 nm and 233 nm. Contrarily to the particle size, the band gap energy of the thoria nanoparticles decreased with the doping/capping process using arsenic (As(III))/cysteine (Cyst). The room-temperature photoluminescence excitation spectra were featured by two bands located at 268 nm for both pure and As-doped thoria nanoparticles and at 352 nm for all thoria-based nanoparticles studied, recording the photoluminescence emission at 500 nm. The characteristic wavelengths of the photoluminescence emission spectra were at 325 and 385 nm for the pure and As-doped thoria nanoparticles, while only the band at 385/415 nm was noted for the Cyst-capped thoria nanoparticles, with slightly red shift depending on the excitation wavelength.