Super Broadband-Sensitive Upconversion in Tm and Ni Codoped Perovskites. (11th February 2019)

• Record Type: Journal Article
• Authors: Luitel, Hom Nath; Mizuno, Shintaro; Takeda, Yasuhiko
• Other Names: Sheu Jinn Kong Academic Editor.
• Is Part Of: International journal of photoenergy. Volume 2019(2019)
• Publication Date: 2019-02-11
• Subjects: Photochemistry -- Periodicals; Photobiology -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Photochimie; Photobiologie; Chimie physique et théorique; Chemistry, Physical and theoretical; Photobiology; Photochemistry; Electronic journals; Periodicals; 541.35
• DOI: 10.1155/2019/7679182
• Languages: English
• ISSNs: 1110-662X

Abstract

Abstract : We investigated broadband-sensitive upconversion (UC) processes in a series of Tm- and Ni-sensitized ABO3 (A = Ca/Sr/Ba and B = Ti/Zr/Hf) perovskites. We have designed combinations of the sensitizers and host cations such that super broad solar radiation ranging from 900 nm to nearly 2000 nm can be efficiently upconverted to 800 nm and shorter wavelengths. The Ni 2+ ions located at the center of O 2− octahedra absorbed photons in the 900–1500 nm range and transferred those energies to the nearby Tm 3+ ions. The Tm 3+ ions upconverted those energies at 800 nm, along with the energies absorbed by themselves in the 1100–1250 and 1550–2000 nm ranges, exhibiting super broadband sensitivity. Among the ABO3 :Tm, Ni (A = Ca/Sr/Ba and B = Ti/Zr/Hf) upconverters, CaTiO3 :Tm, Ni exhibited the best performance due to its most distorted crystal structure, which intensified the emission and absorption extents by increasing the optical transition probabilities of Tm 3+ and Ni 2+ ions. Introduction of alkali ions at the Ca 2+ sites and Nb 5+ ions at the Ti 4+ sites intensified the UC emission by many folds, mainly due to a charge balance mechanism. At the same time, bigger and smaller codoped alkali ions created an asymmetric crystal field around the active ions and further enhanced the UC emission. Importantly, the upconverted photons are within the absorption edges of GaAs, Cu2 ZnSnS4, and dye-sensitized solar cells making wider applications of these upconverters besides crystalline Si solar cells.