Optimization of quantum-dot light source and detection of the simulants of chemical warfare agent

Abstract

Near-infrared (NIR) PbS quantum-dot (QD) light sources were prepared by combining a chip-on-board (COB) LED chip with a PbS QD solution and ultraviolet (UV) glue. A method through adjusting the ratio of QD solution to UV glue to optimize the performance of the light source and match chemicals absorption spectra was presented in this paper. The relationship and trade-offs between different QD–glue ratios of the PbS QD light sources and the performance parameters including light intensity and PL peak were investigated at external voltages from 12.4 V to 13.4 V. The experimental results suggest that the PbS QD light intensity was the highest when the QD–glue ratio was 1:9. The light source was stable when the QD–glue ratio no more than 1:9. The PL peak of the QD light source were redshifted as the QD-glue ratio increased. In addition, two QDs materials with PL peak of 1172 ± 20 nm and 1380 ± 50 nm were selected to prepare the light source. The PL peak of the QD light source can match the absorption peak of the simulants of chemical warfare agents including Dimethyl Methylphosphonate (DMMP) and Dichloromethane (CH2Cl2) accurate by changing the QD-glue ratio. The results suggest that the QD light source optimized were match the sample well, which achieved qualitative detection. And the standard curves were establish, realized the quantitative detection of the sample concentration from 2% to 100%. Therefore, adjusting the QD–glue ratio is a feasible and effective method to improve the luminous intensity, the stability, and the Selectivity of sample detection of the QD light source. And the QDs with tunable emissions have great potential for multiple chemicals detect