陶瓷学报2025，Vol.46Issue(5)：951-958,8.DOI:10.13957/j.cnki.tcxb.2025.05.009
SiO2包覆CsPbBr3纳米晶的制备及其荧光稳定性研究
Preparation and Fluorescence Stability of SiO2-coated CsPbBr3 Nanocrystals
摘要
Abstract
[Background and purposes]All-inorganic cesium lead halide perovskite NCs have garnered substantial attention,due to their exceptional PL properties,including high PLQY,long carrier lifetime,tunable emission wavelengths and high color purity.These characteristics render them highly suitable for applications in LEDs,display devices,solar cells and other optoelectronic fields.However,the intrinsic instability of these NCs,particularly their sensitivity to moisture,light,oxygen and temperature,severely limits their practical applications.To address this challenge,various strategies,including doping,surface modification and encapsulation,have been explored.Among these,surface encapsulation with SiO2 has shown great potential in enhancing the stability and performance of CsPbX3 NCs.This study is aimed to study the surface coating strategies of CsPbBr3 NCs using SiO2,thus optimizing the encapsulation process to improve their fluorescence stability and quantum yield. [Methods]CsPbBr3 NCs were synthesized by using a supersaturation recrystallization method at room temperature.Lead bromide and cesium acetate were used as the precursors,while oleic acid and oleylamine served as capping ligands to control grain growth and surface properties of the NCs.DMF was employed as the solvent,and toluene was used as the antisolvent to induce recrystallization and precipitation of the CsPbBr3 NCs.The molar ratio of Pb/Cs was systematically varied to identify the optimal composition for the fluorescence performance.Then,the synthesized CsPbBr3 NCs were coated with a SiO2 shell using TEOS as the silicon source.The effects of Pb/Cs molar ratios and TEOS dosages on fluorescence properties and stability of the CsPbBr3@SiO2 composites were evaluated.The samples were characterized by using XRD,TEM,FTIR,and PL spectroscopy,to reveal their crystal structure,morphology,chemical composition and optical properties. [Results]XRD results confirmed the successful formation of CsPbBr3 and the presence of a SiO2 shell in the composites.TEM results revealed that the CsPbBr3 NCs were uniformly coated with a SiO2 layer,with particle sizes ranging from 9 nm to 14 nm.FTIR data identified the characteristic Si-O-Si stretching vibrations,confirming the successful formation of the SiO2 shell.PL spectra further validated the enhanced fluorescence properties of the CsPbBr3@SiO2 composites,as compared with the bare CsPbBr3 NCs.The CsPbBr3 NCs synthesized with a Pb/Cs molar ratio of 1.8 exhibited the highest PLQY of 46.9%.This ratio was identified as optimal for achieving the highest fluorescence performance.The PLQY of CsPbBr3@SiO2 composites was significantly enhanced when the TEOS/Pb molar ratio was optimized to 0.3,with a reaction time of 4 h.Under these conditions,the PLQY of the composites reached 62.2%.This improvement was attributed to the effective passivation of surface defects by the SiO2 shell,which reduced non-radiative recombination and enhanced overall fluorescence efficiency.Stability of the CsPbBr3 NCs was significantly improved by the SiO2 coating.When exposed to ethanol for 30 min,the PL intensity of bare CsPbBr3 NCs decreased to 21.5%of the initial value,while CsPbBr3@SiO2 composites retained 85.2%of their initial PL intensity.This result demonstrated that the SiO2 shell effectively isolated the NCs from the polar solvent environment,thereby enhancing their stability. [Conclusions]An effective strategy for enhancing the fluorescence stability and PLQY of CsPbBr3 NCs through SiO2 coating was demonstrated.The optimized synthesis conditions,including a Pb/Cs molar ratio of 1.8 and a TEOS/Pb molar ratio of 0.3,led to a maximum PLQY of 62.2%for the CsPbBr3@SiO2 composites.The SiO2 shell effectively passivated surface defects,reduced non-radiative recombination and provided a robust barrier against environmental degradation,significantly improving the stability of the NCs in polar solvents such as ethanol.These findings highlight the potential of CsPbBr3@SiO2 composites for practical applications in optoelectronic devices.Future work will focus on addressing the toxicity of lead-based perovskites and exploring more efficient encapsulation methods to further enhance material performance.关键词
全无机钙钛矿/CsPbBr3 纳米晶/SiO2 包覆/量子产率Key words
fully inorganic perovskite/CsPbBr3 nanocrystalline/SiO2 coating/quantum yield分类
化学化工引用本文复制引用
武文魁,陆雨晨,梁梦标,谢志翔,王三海,陈婷..SiO2包覆CsPbBr3纳米晶的制备及其荧光稳定性研究[J].陶瓷学报,2025,46(5):951-958,8.基金项目
国家自然科学基金(52062019) （52062019）
江苏省高等学校基础科学(自然科学)研究重大项目(24KJA430013) （自然科学）
江西省自然科学基金(20232BAB204015) （20232BAB204015）
江苏省高校青蓝工程. （）
