Microstructural Control of Soluble Acene Crystals for Field-Effect Transistor Gas Sensors.

Microstructural control during the solution processing of small-molecule semiconductors (namely, soluble acene) is important for enhancing the performance of field-effect transistors (FET) and sensors. This focused review introduces strategies to enhance the gas-sensing properties (sensitivity, recovery, selectivity, and stability) of soluble acene FET sensors by considering their sensing mechanism. Defects, such as grain boundaries and crystal edges, provide diffusion pathways for target gas molecules to reach the semiconductor-dielectric interface, thereby enhancing sensitivity and recovery. Representative studies on grain boundary engineering, patterning, and pore generation in the formation of soluble acene crystals are reviewed. The phase separation and microstructure of soluble acene/polymer blends for enhancing gas-sensing performance are also reviewed. Finally, flexible gas sensors using soluble acenes and soluble acene/polymer blends are introduced, and future research perspectives in this field are suggested.

Preparation of Janus silica particles with organo-silane compounds using polystyrene trapping layer.

In this study, the Janus silica particles were prepared by grafting reaction based on the sol-gel method. Before the surface modification reaction, the silica particles were trapped in the PS layer and some fraction of their surface were only reacted with APTES. XPS analysis confirmed that the nitrogen compounds were introduced on the surface of the Janus particles, and the curve fitting of nitrogen confirmed that the compounds were the amine groups. From the result of SEM analysis, there were no differences in the size and the surface morphology and no formation of the APTES clusters. Based on these results, it was confirmed that the Janus silica particles were prepared using PS trapping layer.