TY - JOUR
T1 - White light-emitting ZnO nanoparticles exhibiting color temperature tunability with near UV excitation and high color rendering
AU - Lewis, Prinston Melroy
AU - Hebbar N., Deepak
AU - Choudhari, K. S.
AU - Kulkarni, Suresh D.
N1 - Funding Information:
We gratefully acknowledge financial support from SERB, DST, Govt. of India through the projects SB/S2/CMP-017/2014 and SB/FT/CS-123/2013; Joint Manipal Academy of Higher Education and DST-FIST (Govt. of India) Program via approval letter SR/FST/PSI-174/2012; From I-CUP, the Indian Cluster for Ultrafast Photonics, supported by the Office of the Principal Scientific Adviser to the Government of India, for providing UV?VIS?NIR spectrophotometer; DST-SAIF Cochin and DST PURSE Laboratory, Mangalore University, Mangalagangotri for providing electron microscopy. Prinston Melroy Lewis sincerely thanks Manipal Academy of Higher Education for Dr. T. M. A. Pai Scholarship and DOM, Govt. of Karnataka for the fellowship DOM/FELLOWSHIP/CR-76/2018-19.
Funding Information:
We gratefully acknowledge financial support from SERB, DST, Govt. of India through the projects SB/S2/CMP-017/2014 and SB/FT/CS-123/2013 ; Joint Manipal Academy of Higher Education and DST-FIST (Govt. of India) Program via approval letter SR/FST/PSI-174/2012 ; From I-CUP, the Indian Cluster for Ultrafast Photonics, supported by the Office of the Principal Scientific Adviser to the Government of India, for providing UV–VIS–NIR spectrophotometer; DST-SAIF Cochin and DST PURSE Laboratory, Mangalore University, Mangalagangotri for providing electron microscopy. Prinston Melroy Lewis sincerely thanks Manipal Academy of Higher Education for Dr. T. M. A. Pai Scholarship and DOM, Govt. of Karnataka for the fellowship DOM/FELLOWSHIP/CR-76/2018-19.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/2
Y1 - 2022/2
N2 - The development of high-quality white-light phosphor for lighting and their facile synthesis is highly desired. Achieving white-light emission in undoped metal-oxides is in great demand, and hence ZnO being a potential phosphor was explored. However, tailoring defect-oriented emissions that mainly depend on processing conditions is challenging. Annealing effects on ZnO to obtain white-light with completely diminished near band-edge emission is detailed here. A systematic variation of processing temperature, ambient pressure, and ambient gas helped tailor the white-light emission. Optimized ZnO nanophosphors emitted white-light with the near-ideal Commission International de l'Eclairage (CIE) coordinates (x = 0.32, y = 0.33 at λex = 325 nm) and correlated color temperature (CCT) of 6200 K (corresponding to day white-light). Optimized processing conditions achieved neutral white-light (x = 0.33, y = 0.33 at λex = 340 nm) and CCT 5645 K. ZnO nanoparticles exhibit excellent color rendering index (CRI) of >90 and high R9 values up to 97%, essential in efficiently rendering object colors compared to that under sunlight. Phosphor-converted white light-emitting diodes (pc-WLEDs) were fabricated on commercial LEDs using the prepared ZnO nanophosphors. pc-WLEDs emitted neutral and day white-light, well-suited for indoor solid-state lighting devices.
AB - The development of high-quality white-light phosphor for lighting and their facile synthesis is highly desired. Achieving white-light emission in undoped metal-oxides is in great demand, and hence ZnO being a potential phosphor was explored. However, tailoring defect-oriented emissions that mainly depend on processing conditions is challenging. Annealing effects on ZnO to obtain white-light with completely diminished near band-edge emission is detailed here. A systematic variation of processing temperature, ambient pressure, and ambient gas helped tailor the white-light emission. Optimized ZnO nanophosphors emitted white-light with the near-ideal Commission International de l'Eclairage (CIE) coordinates (x = 0.32, y = 0.33 at λex = 325 nm) and correlated color temperature (CCT) of 6200 K (corresponding to day white-light). Optimized processing conditions achieved neutral white-light (x = 0.33, y = 0.33 at λex = 340 nm) and CCT 5645 K. ZnO nanoparticles exhibit excellent color rendering index (CRI) of >90 and high R9 values up to 97%, essential in efficiently rendering object colors compared to that under sunlight. Phosphor-converted white light-emitting diodes (pc-WLEDs) were fabricated on commercial LEDs using the prepared ZnO nanophosphors. pc-WLEDs emitted neutral and day white-light, well-suited for indoor solid-state lighting devices.
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U2 - 10.1016/j.mssp.2021.106284
DO - 10.1016/j.mssp.2021.106284
M3 - Article
AN - SCOPUS:85117714892
SN - 1369-8001
VL - 138
JO - Materials Science in Semiconductor Processing
JF - Materials Science in Semiconductor Processing
M1 - 106284
ER -