TY - JOUR
T1 - Temperature Control of Yellow Photoluminescence from SiO2-Coated ZnO Nanocrystals
AU - Kumar, Narender
AU - Poulose, Vijo
AU - Laz, Youssef Taiser
AU - Chandra, Falguni
AU - Abubakar, Salma
AU - Abdelhamid, Abdalla S.
AU - Alzamly, Ahmed
AU - Saleh, Na’il
N1 - Publisher Copyright:
© 2022 by the authors.
PY - 2022/10
Y1 - 2022/10
N2 - In this study, we aimed to elucidate the effects of temperature on the photoluminescence from ZnO–SiO2 nanocomposite and to describe the preparation of SiO2-coated ZnO nanocrystals using a chemical precipitation method, as confirmed by Fourier transform infrared (FTIR) and powder X-ray diffraction analysis (XRD) techniques. Analyses using high-resolution transmission microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), and electrophoretic light scattering (ELS) techniques showed that the new nanocomposite has an average size of 70 nm and 90% silica. Diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and photoluminescence-excitation (PLE) measurements at different temperatures revealed two emission bands at 385 and 590 nm when the nanomaterials were excited at 325 nm. The UV and yellow emission bands were attributed to the radiative recombination and surface defects. The variable-temperature, time-resolved photoluminescence (VT-TRPL) measurements in the presence of SiO2 revealed the increase in the exciton lifetime values and the interplay of the thermally induced nonradiative recombination transfer of the excited-state population of the yellow emission via deep centers (DC). The results pave the way for more applications in photocatalysis and biomedical technology.
AB - In this study, we aimed to elucidate the effects of temperature on the photoluminescence from ZnO–SiO2 nanocomposite and to describe the preparation of SiO2-coated ZnO nanocrystals using a chemical precipitation method, as confirmed by Fourier transform infrared (FTIR) and powder X-ray diffraction analysis (XRD) techniques. Analyses using high-resolution transmission microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), and electrophoretic light scattering (ELS) techniques showed that the new nanocomposite has an average size of 70 nm and 90% silica. Diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and photoluminescence-excitation (PLE) measurements at different temperatures revealed two emission bands at 385 and 590 nm when the nanomaterials were excited at 325 nm. The UV and yellow emission bands were attributed to the radiative recombination and surface defects. The variable-temperature, time-resolved photoluminescence (VT-TRPL) measurements in the presence of SiO2 revealed the increase in the exciton lifetime values and the interplay of the thermally induced nonradiative recombination transfer of the excited-state population of the yellow emission via deep centers (DC). The results pave the way for more applications in photocatalysis and biomedical technology.
KW - ZnO nanocrystals
KW - nonradiative relaxation
KW - temperature control
KW - time-resolved photoluminescence
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U2 - 10.3390/nano12193368
DO - 10.3390/nano12193368
M3 - Article
AN - SCOPUS:85139904488
SN - 2079-4991
VL - 12
JO - Nanomaterials
JF - Nanomaterials
IS - 19
M1 - 3368
ER -