Microwave Assisted Synthesis of ZnO Nano-Sheets and Their Application in UV-Detector

Abstract

Here we report a low cost electrochemical aqueous solution method for synthesis of high quality two dimensional flat ZnO nano-sheets using standard home use microwave-oven. Independent studies by field emission scanning electron microscopy and high resolution transmission electron microscopy confirm the formation of very thin graphene-like nanosheets of ZnO. The high quality of the sheets is confirmed from a photoluminescence study, which shows the presence of a narrow and sharp band edge emission at 360 nm and the presence of a weak defect related emission peak in the visible region. The conductivity of the nanosheets increases dramatically upon illumination of UV lights as compared to the dark condition. The better crystal quality and excellent photo conductivity ensure these ZnO nanosheets can be used as potential UV detector. It is also found that both response and recovery times of ZnO nano-sheets are very fast and are comparable to those of nanowires and nanorods.

A Facile Thermal-Treatment Route to Synthesize ZnO Nanosheets and Effect of Calcination Temperature

“…Figure 6 , shows SEM images of ZnO nanosheets and the calcination temperature's effect. The results are in agreement with previously reported literature [19] , [22] , [36] . Figure 6(a) and (b) reveal that the product has a nanosheet appearance with a shrunken edges and irregular morphology structure at low temperature.…”

“…Various methods have been previously reported on the synthesis of ZnO nanosheets with improved chemical and physical properties, such as solvothermal method [15] sol–gel technique [16] , precipitation method [17] , hydrothermal growth (HTG) method [18] , microwave assisted method [19] , hydrothermal method [20] , anodization method [21] , thermal decomposition and reduction method [22] . Further methods also have been reported to synthesis ZnO nanparticles such as Microemulssion method [23] – [26] , microwave method [27] , thermal evaporation [28] , mechanochemical synthesis method [29] , spray pyrolysis [25] and chemical vapour deposition [30] .…”

The influence of calcination temperature on structural and optical properties of ZnO nanoparticles via simple polymer synthesis route

“…Several procedures and methods have previously been reported on the synthesis of ZnO NPs with the aim of improving the chemical and physical behaviours. Such include microwave assisted method [10], thermal evaporation method [11], thermal decomposition method [12], spray pyrolysis [13], chemical vapour deposition [14], hydrothermal growth [15], sol gel technique [16], precipitation method. Insipid that, most of these methods have difficulties in applying for large scale production due to the complicated procedure, high temperature involved, a longer period of reaction, toxic chemical reagent and by product release to the immediate environment at the end of the experiments.…”

Graphene/h-BN/ZnO van der Waals tunneling heterostructure based ultraviolet photodetector

“…Fitted results of 1 τ and 2 τ are 0.84s and 5.26s, respectively. 2 τ is a slow response process may be associated with the oxygen absorption and desorption process in the interface of h-BN/ZnO [43,44]. The energy-band diagrams of graphene/h-BN/ZnO device under reverse bias are shown in Fig.…”