Facile Growth Of Large Area Ultra-long Organic Microwire Array And Their Application In Photodetector Devices

Compare to inorganic counterpart, small molecule organic semiconductingmaterials with tunable molecular design and property modulation have attractedconsiderable attention. The one-dimensional(1D) nanostructures obtained throughconventional method always distributed in a macroscopically random fashion on thesubstrate or in the solution, which made the electrical, photoelectric performanceresearch stay in a single device stage and limited the integrated application.Achievement of large-area fabrication of ultra-long organic MWs arrays means that wedo not need to precisely address the positions of individual1D MWs anymore, but cantreat the aligned MWs as uniform “2D film” and use the mature film device techniques,which can greatly facilitate the device fabrication process and promote the integratedapplications of1D nanostructure.In this thesis, we focused on the large-area fabrication of ultra-long organic MWsarrays and their application in photodetector devices. The main results are summarizedas follows:Firstly, we obtain the large area ultra-long MeSq microwires array through slowlyevaporation induced self-assemble method. The microwires have a width of2.5μm, andheight of320nm. The periodicity of the MWs is8MWs/100μm. The area of themicrowires array could be1×1cm2. The microwires obtained from this method arenearly parallel and oriented to the dewetting direction. Then, we manufacture thenear-infrared photodetector based microwires arrays through Mask assisted PVD(high-vacuum e-beam evaporation system) on the SiO2substrate, and shows outstandingand repeatable photoresponse property. Next, we transfer the microwires arrays to theflexible PDMS substrate with95％transfer rate and manufacture the flexiblenear-infrared photodetector. The flexible NIR photodetectors also exhibited goodphotoresponse performance even after bending to a curvature of1cm-1. These results suggest that ordered MWs film obtained by this strategy have great potential aspromising building blocks for future flexible nano-optoelectronics.Secondly, we obtained large area and ultra-long MeSq microwires arrays throughwetting/dewetting periodicity molecular template assisted evaporation inducedself-assemble method. The width and height of the MWs are3-4μm and550nm,repectively. Ultra-long microwires selectively deposited only on the wettable channel.Therefore we can regulate the spacing of the MWs by altering the spacing of theadjacent wettable channels. We also developed an photoresist strips template assistedevaporation induced self-assemble method via keep the photoresist strip on the substrateto assisted the evaporation induced self-assemble. The width and length of the MWs are2μm and10mm, repectively. Ultra-long microwire will selectively deposited on the twosides of the photoresist strip. We also can regulate the spacing of the MWs by alteringthe spacing of the adjacent photoresist strip. This approach is highly reliable withextremely high reproducibility and stability. MeSq MW arrays can grow perfectly onsides of photoresist strips with any width or spacing, leading to the formation of denseMW films on entire1×1cm2substrate. We manufacture the near-infraredphotodetector based microwires film through Mask assisted PVD (high-vacuum e-beamevaporation system) on the SiO2substrate, and shows outstanding and repeatablephotoresponse property.Thirdly, we obtain the large area and ultra-long fullerene(C60) microwires arraysthrough photoresist channel template assisted evaporation induced self-assemblemethod. C60microwires arrays with1×1cm2area selectively deposited only on thewettable channel. Therefore we can regulate the spacing of the MWs by altering thespacing of the adjacent wettable channels. We also can obtain large area ultra-longmicrowire array on the Au electrode pairs substrate. C60microwires also showsexcellent photoresponse property.