Fong, James (2018) Efficient light emission from MoS2 flakes by in-solution superacid treatment. In: nanoGe Fall Meeting, 2018-10-22 - 2018-10-26, Hotel Meliã Costa del Sol.
Full text not available from this repository.Abstract
Two-dimensional (2D) molybdenum disulphide (MoS2) attracts wide usage in opto electronic/photovoltaic devices due to its direct bandgap of 1.90 eV [1]. Among different monolayer preparation methods, liquid assisted exfoliation is preferred, as it is simple, scalable, convenient and cost-effective than other conventional methods (mechanical exfoliation and chemical vapour deposition etc) [2]. In this work, ultrasonic bath sonication of bulk MoS2 (6-40 µm powder) in iso-propanol/water mixture (70/30 vol %) is followed according to [3]. Full width half-intensity (FWHI) value of 200 meV (from the photoluminescence (PL) emission peak) showed that the exfoliated MoS2 contains 2-3 layers (in agreement with our atomic force microscopy (AFM) results) [4]. Super acid treatment (drop casting) onto MoS2/Si wafer improved the PL by three orders of magnitude. In addition and all-wet treatment process was developed - with the maximum PL enhancement observed to be around 200 times. The result shows that all-wet processing can enable efficient light generation from few layer MoS2, which is promising for applications using 2D inks for optoelectronics.