Generation of Pure Green Up-Conversion Luminescence in Er3+ Doped and Yb3+-Er3+ Co-Doped YVO4 Nanomaterials under 785 and 975 nm Excitation.

Natalia Stopikowska,Przemysław Woźny,Marcin Runowski,Stefan Lis,Peng Du

doi:10.3390/nano12050799

Abstract

Materials that generate pure, single-color emission are desirable in the development and manufacturing of modern optoelectronic devices. This work shows the possibility of generating pure, green up-conversion luminescence upon the excitation of Er3+-doped nanomaterials with a 785 nm NIR laser. The up-converting inorganic nanoluminophores YVO4: Er3+ and YVO4: Yb3+ and Er3+ were obtained using a hydrothermal method and subsequent calcination. The synthesized vanadate nanomaterials had a tetragonal structure and crystallized in the form of nearly spherical nanoparticles. Up-conversion emission spectra of the nanomaterials were measured using laser light sources with λex = 785 and 975 nm. Importantly, under the influence of the mentioned laser irradiation, the as-prepared samples exhibited bright green up-conversion luminescence that was visible to the naked eye. Depending on the dopant ions used and the selected excitation wavelengths, two (green) or three (green and red) bands originating from erbium ions appeared in the emission spectra. In this way, by changing the UC mechanisms, pure green luminescence of the material can be obtained. The proposed strategy, in combination with various single-doped UC nanomaterials activated with Er3+, might be beneficial for modern optoelectronics, such as light-emitting diodes with a rich color gamut for back-light display applications.

Highlights

Up-conversion (UC), anti-Stokes luminescence is a phenomenon where two or more low-energy photons are converted into one photon of higher energy
Our studies show that the excitation wavelength and the presence of sensitizer ions play important roles in achieving pure green UC emission in vanadate nanomaterials
TEM images (Figure 2a,b) show that the obtained compounds were composed of irregular, agglomerated nanoparticles (NPs), and their average sizes were around 94 ± 32 nm for YVO4 : Er3+ (Figure 2c) and 66 ± 17 nm for

Summary

Introduction

Up-conversion (UC), anti-Stokes luminescence is a phenomenon where two or more low-energy photons are converted into one photon of higher energy. Our studies show that the excitation wavelength and the presence of sensitizer ions play important roles in achieving pure green UC emission in vanadate nanomaterials These results and the developed strategy may be important from the point of view of electronics and materials engineering, in utilizing vanadates and other Er3+ -doped UC nanomaterials (e.g., molybdates and tungstates) excited at higher-energy NIR lasers. This is because the possibility of generating pure-color emission can be used for the manufacturing of modern optoelectronics, new light sources, optically active components of various devices etc

Materials

Characterization

Structure and Morphology

Luminescence Properties

Conclusions