PbSe量子点荧光匹配气体吸收光谱方法研究

Research on Spectrum Matching Method for PbSe Quantum Dots Luminescence Spectrum and Gas Absorption Spectrum

PbSe量子点（PbSe-QDs）是红外波段的典型纳米材料,其具有大的玻尔半径、小的体材料禁带宽度（玻尔半径是46nm,体材料禁带宽度是0.28eV）,因此,在近红外区域,PbSe-QDs具有强大的尺寸受限效应和较高的量子产出率。本文对不同尺寸的PbSe量子点的荧光光谱特性进行了研究,提出了一种通过调节PbSe量子点的量子尺寸匹配气体吸收光谱的方法。采用配位溶剂的方法制备了尺寸为4.6和6.1nm的PbSe量子点,将该PbSe量子点沉积到GaN发光芯片上并经过紫外光照处理和固化后制成了光致发光的近红外光源,其中4.6nm的PbSe-QDs的沉积厚度为671.5μm,而6.1nm的PbSe-QDs的沉积厚度为48μm。将制成的近红外光源应用到C2H2气体和NH3气体的检测实验中,实验结果表明,通过改变PbSe量子点的尺寸可以调节光源光致发光峰的位置,从而覆盖目标气体在近红外波段的吸收谱线。4.6nm的光源发射光谱包含了1 500~1 550nm之间的C2H2气体的全部的吸收谱;6.1nm的光源发射光谱包含了1 900~2 060nm之间的NH3气体的全部的吸收谱。这种利用PbSe量子点尺寸的可调性匹配对应气体吸收谱的方法是可行和有效的,具有广阔的应用前景。

As typical nano metarials in near infrared waveband,PbSe Quantum Dots have a very large exciton Bohr radius of 46 nm and a small band gap of 0.28 eV at room temperature.PbSe QDs have very unique properties,such as the quantum confined optical property,and which possess high photoluminescence（PL）quantum yield（QY）with size dependent tunable wavelength emissions.By analyzing the luminescence spectrum of PbSe Quantum Dots,a method through adjusting the particle size of PbSe Quantum Dots（QDs）to match gas absorption spectrum was presented in this paper.4.6and 6.1nm PbSe QDs were synthesized and deposited on the GaN chip to fabricate the NIR QDs light sources.The PbSe QDs-UV glue composites thickness was determined to be 48.0and 671.5μm for 6.1and 4.6nm PbSe QDs.The NIR QDs were used to detect the C2H2 and NH3gas.The experiments show that the PL spectrum of 4.6nm NIR QDs can cover the entire absorption spectrum of C2H2gas（from1 500 to 1 550nm）and the PL spectrum of 6.1nm NIR QDs can cover the entire absorption spectrum of NH3gas（from 1 900 to 2 060nm）.By changing the quantum size of QDs,the PL peak of the NIR QDS light source can be adjusted to cover the absorption peak of different gases.The matching method presented in this paper is efficient and feasible,which has great application potential in gas detection.