Kinetic Study of the Thermal Quenching of the Ultraviolet Emission in Zn2GeO4 Microrods. Issue 6 (16th March 2022)

• Record Type: Journal Article
• Authors: Dolado, Jaime; Hidalgo, Pedro; Méndez, Bianchi
• Is Part Of: Physica status solidi. Volume 16:Issue 6(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-16
• Subjects: microrods -- photoluminescence -- temperature dependence luminescence -- thermal quenching -- zinc germanate; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.202100613
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Zn2 GeO4 microrods obtained by thermal evaporation of a compacted powder mixture of ZnO and Ge exhibit quite intense UV luminescence at low temperatures. Herein, the luminescence properties of Zn2 GeO4 microrods are studied for 2:1 and 1:1 ZnO:Ge ratio in the precursor mixture. In both cases, Zn2 GeO4 microrods of high crystal quality produce a 355 nm emission under aforementioned bandgap excitation conditions at low temperatures. However, this emission vanishes at room temperature (RT) in the 1:1 samples while it is kept in the 2:1 ones. Herein this work, the thermal quenching of the UV luminescence is studied by means of steady and time‐resolved photoluminescence techniques from 4 K up to RT for both Zn2 GeO4 microrods. The analysis of the results leads us to conclude that although the luminescence mechanisms are the same in both cases, a higher decay rate is observed in the 1:1 in both intensity and lifetime, which explain the observed thermal quenching at RT. Abstract : The luminescence of Zn2 GeO4 microrods obtained by thermal evaporation using a different ZnO:Ge ratio (1:1 and 2:1) is studied. The UV emission vanishes at room temperature (RT) in the 1:1 sample, while survives in the 2:1 one up to RT. Temperature‐dependent photoluminescence (PL) measurements show an abrupt PL quenching and allow assessment of the non‐radiative channel in both samples.