Flexible Photodetector Based On Hetero-structures Of Molybdenum Ditelluride And Molybdenum Disulfide

With the rapid development of information technology,electronic systems based on rigid substrates have gradually become difficult to meet people’s needs for portability and wearability of consumer electronics.Therefore,researchers have begun to develop elec-tronic and optoelectronic devices and systems based on flexible substrates.The two-di-mensional（2D）layered materials represented by graphene has excellent mechanical flexi-bility because its thickness is on the scale of a single atomic layer and the inner-plane atoms are connected by strong covalent bonds.Coupled with its excellent electrical and optical properties,2D materials are considered to be one of the most potential materials for the development of flexible electronics.However,the preparation process of flexible devices based on 2D materials is not yet mature;and the electrical and optical properties of 2D materials are easily changed by stress/strain,resulting in the instable performance of the flexible devices based on 2D materials,which seriously affects its practical applicationIn response to the above problems,this thesis studies a flexible photodetector based on heterostructures of molybdenum ditelluride（Mo Te₂）and molybdenum disulfide（Mo S₂）.Based on this study,a set of CMOS compatible manufacturing processes for 2D material based flexible devices is established,and the influence of strain on the photoelectric re-sponse of the detector under light illumination of different wavelengths is analyzed.Finally,stable photoelectric detection under strain interference conditions is realized.The main research contents are as follows:1.Established a set of CMOS compatible manufacturing processes for 2D material based flexible electronic devices.The process flow mainly includes the preparation of flexible substrates,the transfer of 2D materials,and the deposition of material electrodes.It solves the manufacturing problems caused by substrate deformation,charge accumula-tion,tip discharge and other phenomena in the manufacturing process of flexible electronic devices,and provides a technical reference for the construction of stable and durable 2D nanomaterial electronic devices on flexible substrates.2.Designed and prepared a flexible photodetector based on Mo Te₂/Mo S₂ heterostruc-ture,and realized photodetection without interference by substrate strain.The strain distri-bution of the entire device under the condition of substrate bending is simulated,which suggests that the strain on the junction area is similar to the strain on the substrate.On this basis,a four-electrode device structure is designed.By measuring the signals in the junc-tion area and the resistance area simultaneously,the strain signal was successfully distin-guished from the light response signal,and the photoelectric detection under the strain in-terference condition of the flexible substrate was realized.