Improving luminescence characteristics of Ni2+ doped CsPbX3 (X = Br/I, I) quantum dots in borogermanate glass for wide color gamut display

Abstract

For wide gamut backlight display application, main problems of CsPbX3 (X = Br/I, I) quantum dots (QDs) glasses as red emission materials are too long emission wavelengths, low luminescence intensity and worse uniformity. The full width at half maximum (FWHM) and decay time should also be considered. Here, Ni2+ doped CsPbX3 (X = Br/I, I) QDs in borogermanate glasses have been successfully fabricated by melt quenching and heat treatment. Transmittance, absorbance, photoluminescence (PL), PL excitation (PLE), PL decay and PL temperature characteristics are measured. By Ni2+ doping in the CsPbX3 (X = Br/I, I) QDs glasses (QDGs), PL intensity is significantly improved to higher level of 106–107 counts (enhanced by 1.6–1.7 times). The peak wavelength is adjusted to suitable range of 630–650 nm by double anion CsPb(Br/I)3 QDs. The uniformity is greatly improved by using suitable composition and concentration of CsPbX3 (X = Br/I, I) QDs. In addition, the FWHM of 32–46 nm is sufficiently narrow. The PL decay shows sufficiently short lifetime of less than 100 ns. The PL temperature dependence fitting shows large exciton binding energy 376–400 meV. For wide color gamut display application, we have used three primary colors with the standard blue, green and red lights in NTSC standard, and the red light has been replaced by using perovskite CsPbX3 (X = Br/I, I) QDGs. For the perovskite CsPbX3 (X = Br/I, I) QDGs emitted at 667 nm and 644 nm, the color gamut area has been increased by 11% and 9%, respectively. The results indicate that the red light QDG materials can be applied to wide color gamut display.