CuInS₂/ZnS量子点液芯光纤发光性质的温度稳定性研究

Research on the Temperature Stability of Emission Properties of CuInS₂/ZnS Quantum Dot Liquid-Core Fibers

摘要: 量子点材料由于具有优异的光电性质，被广泛应用于发光二极管、太阳能电池、生物标记等领域。然而，大多数金属如镉、铅、砷等具有较高毒性，对环境产生极大污染。所以本文基于绿色、无毒、环保的理念，以高温热分解法合成了裸核CuInS₂量子点和包壳时间分别为60 min、70 min、80 min、90 min的CuInS₂/ZnS核壳量子点。利用压力差法制成量子点掺杂的液芯光纤，在20~80℃环境温度下，通过改变相关参数进行温度稳定性的测试。研究结果表明，当以包壳时间为90 min量子点作为光纤掺杂剂时，光纤发光强度最强，且随温度增加衰减得最慢，即温度稳定性最高。对于光纤长度、光纤直径和掺杂浓度较小的光纤，发光强度虽然减弱，但是进一步提升了温度稳定性。另外，在相同参数下对比了甲苯和四氯乙烯两种溶剂对温度稳定性的影响，发现以四氯乙烯为溶剂的光纤发光强度更强，其峰值波长和峰值强度随温度变化更加稳定。在最优参数体系下(包壳时间90 min样品、光纤长度30 cm、光纤直径50 μm、掺杂浓度10 mg/mL)，随温度的增加，光纤发光的峰值波长相对红移幅度仅0.38%，强度相对衰减率3.91%，且强度随温度变化接近线性衰减；而非最优参数体系红移幅度与衰减率分别达0.96%、90.54%，且存在明显的非线性衰减。

Abstract: Quantum dot (QD) materials, owing to their exceptional optoelectronic properties, have been widely applied in fields including light-emitting diodes (LEDs), solar cells, and biological labeling. However, most metals such as cadmium, lead, and arsenic exhibit high toxicity, posing severe environmental pollution risks. Thus, guided by the principle of green, non-toxic, and environmental friendliness, this study synthesized bare core CuInS₂ QDs and CuInS₂/ZnS (CIS/ZnS) core-shell QDs with shell formation times of 60 min, 70 min, 80 min, and 90 min via high-temperature thermal decomposition. Using the pressure difference method, CIS/ZnS core-shell QD-doped liquid-core fibers were fabricated, which were then placed in an ambient temperature range of 20˚C to 80˚C for temperature stability testing by adjusting relevant parameters. The results show that when QDs with a 90 min shell growth duration were employed as the fiber dopant, the fiber displayed the strongest emission intensity and the slowest attenuation with increasing temperature, corresponding to the highest temperature stability. For fibers with shorter lengths, smaller diameters, and lower doping concentrations, although the emission intensity was reduced, the temperature stability was further enhanced. Additionally, the effects of two solvents, toluene and tetrachloroethylene, on temperature stability were compared under the same parameters. It was found that the optical fiber doped with tetrachloroethylene had a stronger emission intensity, and its peak wavelength and peak intensity were more stable with temperature changes. Under the optimal parameter system (sample with 90 min shell growth, 30 cm fiber length, 50 μm fiber diameter, and 10 mg/mL doping concentration), the relative redshift of the fiber’s emission peak wavelength was only 0.38% with increasing temperature, and the relative intensity attenuation rate was 3.91%, following a nearly linear dependence on temperature. In contrast, the non-optimal parameter system showed a redshift of 0.96% and an attenuation rate of 90.54%, accompanied by significant nonlinear attenuation.