Tuning the Red Emission to Instigate Intrinsic White‐Light Emission in Single‐Phase Phosphor with Excellent Color Rendering Index. Issue 24 (4th November 2022)

• Record Type: Journal Article
• Authors: Dehury, Asish K.; Behera, Santosh Kumar; Chirauri, Satya Kamal; Basu, Suddhasatwa; Chaudhary, Yatendra S.
• Is Part Of: Chemistry, an Asian journal. Volume 17:Issue 24(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-04
• Subjects: Intrinsic white light emission -- single phase phosphor -- copper doping -- zinc sulphide -- photoluminescence; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.202200948
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: There is ever‐growing interest to develop intrinsic white light emitting single‐phase phosphors that have high CRI, devoid of bluish tinge, ease of synthesis and are scalable. Herein, manipulating vacuum pressure to instigate white light emission in Cu 2+ ‐doped‐ZnS phosphors is reported. The detailed X‐ray diffraction and electron microscopy confirm the cubic phase of Cu 2+ ‐doped‐ZnS phosphor having agglomerated particles (∼130–150 nm). The incorporation of Cu 2+ in the ZnS lattice is substantiated by the anti‐Stokes shift of Raman peaks and shifting of XRD peaks to higher 2θ values. Upon increasing Cu 2+ doping concentration, the resulted decrease in the FWHM of XRD peaks implies shrinkage of the ZnS lattice. Interestingly, by tailoring the excitation wavelength, the stoichiometry of dopant ion, and defect states by varying the vacuum pressure, the optimized ZSC‐3 (3% Cu 2+ ‐doped‐ZnS) displays the origin of clear blue, green and red emission bands, consequently giving rise to white light emission (CIE values: 0.345:0398). The PLQY and average lifetime calculated for ZSC‐3 are 5.98% and 1.5 ms, respectively. Such intense white light emission prompted to fabricate a prototype using a 310 nm UV LED. It exhibits high CRI (97) and warm CCT (4538 K), meeting highly desired values for a white light‐emitting phosphor for different lighting and electroluminescence applications. Abstract : White light emission arising from synthesized single‐phase Cu‐doped ZnS phosphor by instigating the red emission stemming from optimized doping concentration of Cu 2+ and defect engineering is reported.