Excellent exciton luminescence of CsPbI3 red quantum dots in borate glass

We have fabricated CsPbI3 perovskite quantum dots in a borate glass by melt-quenching technique. Three representative samples with different treatment conditions are investigated. As treatment condition enhances, energy gap is extracted as 1.75-1.76 eV, and photoluminescence peak is adjustable from 675 to 691 nm. Full width at half-maximum (FWHM) varies from 43 to 37 nm. PL intensity first increases and then decreases with increasing excitation wavelength, but the peak wavelength and line-shape are independent. High PLQY values of 23.8%-61.4% are obtained. The high PLQY values are attributed to good crystal quality and less energy dissipation. PL lifetime is fitted as 24.0-28.2 ns and 100.2-123.0 ns for short and long lifetime components in bi-exponential function. For temperature from 25 to 125 degrees C, PL intensity decreases, but it is reversible. Exciton binding energy is extracted in the level of 375-454 meV. The FWHM broadening from 39 to 49 nm and peak blue-shift from 690 to 685 nm are investigated.