Inorganic perovskite quantum dots (PQDs) have garnered significant interest due to their exceptional optical characteristics, including narrow emission spectra and high photoluminescence quantum yield (PLQY). Despite these advantages, PQDs are often hindered by environmental instability, particularly notable in CsPbI₃ QDs which exhibit lower PLQY and susceptibility to phase transitions at ambient conditions, compromising optical performance. To address these challenges, enhancing the stability and optical properties of CsPbI₃ QDs is crucial. Current research focuses on methods such as ligand exchange, encapsulation, and ion doping, with the latter proving particularly effective in improving PLQY and stability. Ion doping, involving substitution at A, B, or X sites, can mitigate Pb toxicity, alter bond lengths, and enhance phase stability, thereby significantly impacting quantum dot performance. Initial CsPbI₃ QDs typically demonstrate a PLQY of 50% to 60% but suffer rapid fluorescence quenching within ten days in environmental settings. This study proposes Zn ion doping as a promising strategy to augment the optical properties of perovskite quantum dots.This article employs a high-temperature thermal injection method for the synthesis of Cs-oleate precursors. Initially, Cs-oleate precursors are synthesized and subsequently rapidly injected into a high-temperature octadecene solution containing PbX₂, ZnI₂ and ligands. The reaction proceeds for a few seconds before the mixture is quenched in an ice water bath. Various molar ratios of ZnI₂/PbI₂ can be adjusted to achieve a series of CsPb_1-xZn_xI₃ (0 < x < 1) quantum dots.Due to the partial substitution of Pb with Zn, the lattice of quantum dots (QDs) gradually contracts with increasing ZnI₂ concentration, while the overall cubic structure of the QDs remains unchanged. This modification enhances the radiative recombination rate and effectively mitigates defect states. The maximum enhancement in photoluminescence quantum yield (PLQY) reaches 98%, accompanied by improved stability(Fig.3(b)). Original CsPbI₃ QDs exhibit complete fluorescence quenching within ten days at room temperature, whereas Zn-doped CsPbI₃ QDs maintain over 80% of their initial PLQY under the same conditions(Fig.3(d)). Transmission electron microscopy (TEM) analysis shows that despite the addition of ZnI₂ precursor, the QDs retain their cubic morphology, with the average particle size decreasing from 18.9 nm to 17.6 nm. This size reduction is attributed to the inhibitory effect of I ions on further QD growth. The interplanar spacing of the QDs decreases from 3.16 Å to 3.13 Å, indicating lattice contraction induced by Zn doping. X-ray diffraction (XRD) patterns confirm that Zn-doped CsPbI₃ QDs exhibit no new diffraction peaks compared to pure CsPbI₃ QDs, but show a gradual shift of peaks towards larger angles, indicating successful substitution of Pb by Zn ions. Analysis of time-resolved photoluminescence (TRPL) spectroscopy reveals that CsPbI₃ QDs have an average fluorescence lifetime of 138.44 ns, while Zn-doped CsPbI₃ QDs exhibit a shorter lifetime of 103.61 ns(Fig.3(e)), attributed to the suppression of halogen vacancy defects and shallow-level states by Zn doping(Tab.1). This doping strategy effectively passivates surface defects and enhances the optical properties of CsPbI₃ QDs.In this study, CsPbI₃ quantum dots doped with Zn²⁺ were successfully synthesized using ZnI₂ via the thermal injection method. The incorporation of Zn enhanced the phase stability of CsPbI₃ quantum dots compared to their undoped counterparts. Photoluminescence quantum yield (PLQY) significantly improved from 56% to 98%, with PLQY retention above 80% after 10 days. Subsequently, narrow-emitting Zn:CsPbI₃, CsPbBr₃, and CsPbCl₃ quantum dots were selected as replacements for conventional phosphors in LED color conversion materials. These quantum dots achieved a color gamut of 135.22% based on the National Television Standards Committee (NTSC) standard(Tab.2), highlighting their promising applications in LED display technologies.