P2NG.10 - PbS Colloidal Quantum Dots-Sensitized MoS2 Nanosheets Hybrid Gas Sensors

17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
P-2 - Nanomaterials for Gas Sensing
J. Liu, B. Zhang, Z. Hu, S. Yang, N. Gao, H. Liu - School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei (China)
863 - 864


The hybrid 0D-2D architecture has emerged as a material platform for designing the high-performance electronic and optoelectronic devices. While having a very high in-plane carrier mobility which may serve as the high charge transport way, 2D nanomaterials, such as MoS2 nanosheets, are also known to exhibit extremely sluggish response and incomplete recovery to the initial state during operation at room temperature. Instead, colloidal quantum dot (CQDs) solids usually have a large, sensitive surface area as well as the quantum size effect tuning, offering a unique opportunity to overcome the bottleneck of 2D MoS2-based devices which is highly desirable for gas sensing at room temperature. Motivated by this strategy, we constructed PbS CQDs-sensitized 2D MoS2 hybrid structure for NO2 gas sensing. The p-type PbS CQDs with bandgaps ranges from 0.7 eV to 1.4 eV was tuned and the energy band alignment with the n-type MoS2 was investigated to achieve optimal gas-sensing
response. Then PbS/MoS2 hybrid gas sensors exhibited a higher response toward NO2 compared to the pristine MoS2 owing to the effective sensitization with PbS CQDs. Sensing mechanism was also proposed and we demonstrated that it was the synergistic effect by excellent access of gas molecules to highly active sensitizing PbS CQDs surfaces, combining with the superb electron transport in MoS2 nanosheets that made a great enhancement of the gas-sensing performance.