Patterned Processing And Device Applications Of Organic Optoelectronic Materials

Organic?-conjugated semiconductor materials,which possess both mechanical flexibility and optoelectronic properties comparable to those of conventional inorganic semiconductor materials,hold great potential for future applications in optoelectronic functional devices.Due to the long-range ordered molecular arrangement,the organic single-crystal structure is capable of maintaining efficient carrier transport and long photocarrier lifetime thanks to the suppression of defect generation,which plays an important role in improving the efficiency of optoelectronic devices.However,the processing of ordered assemblies of organic materials is still challenging at present due to the harsh processing conditions prevailing in conventional inorganic material processing methods,such as etching and high-temperature vapor deposition,which are not applicable to organic material processing.Therefore,the development of a low-cost,mass-producible,and simultaneously high-precision patterning processing strategy is significant for the development of complex design and functionalized applications of micro/nanostructures of organic optoelectronic materials.The solution processing technology is highly universal for organic materials,however,the disorderly flow of liquid and irregular liquid film rupture tend to disorderly accumulation and assembly of materials.Here we introduce a new method based on super-wetting interface to regulate liquid bridge induced assembly.The controlled flow of liquid and fixed-point partitioning of liquid film are induced by regulating the pro-and anti-liquid state of the interface,which leads to the orderly assembly of structural units in solution in a restricted domain,and achieves the preparation of patterned arrays of organic materials with controlled large-area morphology.Furthermore,the dimensional control of the organic material array structure is achieved by regulating the parameters such as ambient temperature,humidity,solution concentration,and solvent surface tension.The specific results are as follows:1.We have successfully prepared micro-structured interfaces with asymmetric super-wettability as a basis for the development of a pervasive capillary gradient-induced assembly patterned processing technique and further investigated the mechanism of this strategy.Based on this approach,we have precisely assembled tunable 1D linearly structured organic semiconductor nanowire arrays with different curvatures,high crystallinity and good homogeneity.This versatile strategy allows for the efficient preparation of deterministically patterned semiconductor polymers with tunable central arc angles,arc radii,widths and thicknesses.In addition,the strategy enables the fabrication of designs with different strain engineering geometries ranging from simple curved structures to complex layered fractals.2.We have prepared 1D semiconductor polymer microstructure arrays with precisely patterned,highly ordered,regularly aligned and large area size homogeneity based on the solution-processed capillary gradient-induced assembly method,which was extended according to the material mechanical property advantages,resulting in high electronic properties and high stretchability for organic field-effect transistors(OFETs)applications.The P-type(P3HT,PDVT-10)and N-type(P(NDI2OD-T2))nanowire arrays were designed with high strain performance structures and prepared on flexible substrates with up to 100%stretchability,respectively.Moreover,OFETs were prepared based on this patterned design,and in the direction parallel or perpendicular to the charge transport direction,the stretchable semiconductor nanowires were able to topographically change to release strain through effective topography without causing significant electrical losses.With an average initial carrier mobility of 2.2 cm² V s^-1,this intrinsically stretchable transistor exhibits exceptional stability with minimal change in electrical properties when subjected to 50%strain for1000 cycles.Ideas for highly stable stretchable electronic devices are provided.3.We used capillary liquid bridge-induced assembly to control the large area-limited crystallization and oriented growth of organic one-dimensional(1D)single crystal arrays with aligned orientation and single orientation.By adjusting the concentration and pressure,the three-dimensional dimensions of the organic 1D arrays can be controlled from 2.9 to 5.8?m in width and 1.2?m to 110 nm in height.Photodetectors based on such organic 1D arrays exhibit stable performance with an on/off ratio of 180 and a responsivity of 4.99 m A W^-1.Based on the large-area photodetector arrays,an integrated 20 x 20 high precision multiplexed image sensor for capturing the optical signals of the capital letters"A","B"and"C".This research will open up opportunities for the large-scale fabrication of organic single-crystal semiconductors towards integrated optoelectronics.