Blending organic semiconductors with insulating polymers has been known to be an effective way to overcome the disadvantages of single-component organic semiconductors for high-performance organic field-effect transistors (OFETs). We show that when a solution processable organic semiconductor (6,13-bis(triisopropylsilylethynyl)pentacene, TIPS-pentacene) is blended with an insulating polymer (PS), morphological and structural characteristics of the blend films could be significantly influenced by the processing conditions like the spin coating time. Although vertical phase-separated structures (TIPS-pentacene-top/PS-bottom) were formed on the substrate regardless of the spin coating time, the spin time governed the growth mode of the TIPS-pentacene molecules that phase-separated and crystallized on the insulating polymer. Excess residual solvent in samples spun for a short duration induces a convective flow in the drying droplet, thereby leading to one-dimensional (1D) growth mode of TIPS-pentacene crystals. In contrast, after an appropriate spin-coating time, an optimum amount of the residual solvent in the film led to two-dimensional (2D) growth mode of TIPS-pentacene crystals. The 2D spherulites of TIPS-pentacene are extremely advantageous for improving the field-effect mobility of FETs compared to needle-like 1D structures, because of the high surface coverage of crystals with a unique continuous film structure. In addition, the porous structure observed in the 2D crystalline film allows gas molecules to easily penetrate into the channel region, thereby improving the gas sensing properties.

In this study, triethylsilylethynyl‐anthradithiophene (TES‐ADT) films with different density of grain boundaries are used for systematic investigation of effects of grain boundary density on gas sensing properties of TES‐ADT field‐effect transistors (FETs). Grain boundary density is simply controlled by changing mixing time of TES‐ADT solution. Higher mixing time leads to higher grain boundary density, and field‐effect mobility decreases with increased grain boundary density. However, gas sensing properties exhibit the opposite behavior. Drain current and field‐effect mobility of FETs based on TES‐ADT film with higher grain boundary density increase much more upon exposure of NO2 with electron withdrawing character. In addition, dynamic gas sensing tests reveal that response rate and sensitivity of a TES‐ADT sensor are enhanced remarkably by an increase of grain boundary density in TES‐ADT films. Grain boundaries provide a pathway for diffusion of gas molecules into channel regions and thus increase of grain boundary density is beneficial for development of highly sensitive OFET gas sensors.

This paper systematically compares the gas sensing properties of organic field‐effect transistors (OFETs) based on patterned 5,11‐bis(triethylsilylethynyl)anthradithiophene (TES‐ADT) films, by adopting TES‐ADT crystal arrays of various shapes and dimensions. The patterning and crystallization of spin‐cast TES‐ADT layers are achieved by the use of a solvent‐containing engraved polydimethylsiloxane (PDMS) mold. Decreasing width of the TES‐ADT pattern enhances gas sensing performance, as well as field‐effect mobility of OFETs. The decreased grain boundary density at narrower line width contributes to the increase of field‐effect mobility. On the other hand, the increased sensing performance is mainly due to the increased area of crystal edges, which provides a diffusion pathway for gas molecules to arrive at the semiconductor‐dielectric interface. This study provides new perspectives on the diffusion pathway of gas molecules in OFET‐based gas sensor, and will be useful for the design of active channel to boost the gas sensing properties of OFETs.

The purpose of this study was to validate the newly developed K-WPPSI-IV using other current IQ tests in common use in Korea such as the K-ABC and K-CTONI-2. Fifty three 2～7 year olds were tested with both the K-WPPSI-IV and K-ABC in a counterbalanced order. Simultaneous, cognitive, information processing as well as acquisition indices of K-ABC were moderately correlated with the total IQ of K-WPPSI-IV, ranging .44～.58. The results of these tests were comparable with US data:Correlations among WPPSI-IV & DAS-II subscales were .31～.67. The correlations among K-WPPSI-IV & K-CTONI-2 subscales in sixty two children ranged from .43～.49. WMI(Working memory index) as well as PSI(Processing speed index) of K-WPPSI showed low correlations with non-verbal IQ. These results indicated that nonverbal IQ does not test processing speed which in turn is very important in WMI & PSI Indices of K-WPPSI-IV. Further studies are needed to broaden the concurrent validities using K-WISC-IV or K-BSID-2. In addition, predictive as well as discriminate validity studies need to be conducted for better understanding of K-WPPSI-IV.Keywords：한국 웩슬러유아지능검사 4판(K-WPPSI-IV), 한국 카우프만검사(K-ABC), 한국 비언어성 지능검사 2판(K-CTONI-2), 공준타당도(concurrent validity).

In article number 1901696, Wi Hyoung Lee and co‐workers report a method to increase sensitivity of the 5,11‐bis(triethylsilylethynyl)‐anthradithiophene (TES‐ADT) gas sensors by adopting TES‐ADT crystal arrays of various shapes and dimensions. The patterning and crystallization of spin‐cast TES‐ADT films are simultaneously achieved by the use of a solvent‐containing engraved polydimethylsiloxane mold. The increased sensing performance in patterned TES‐ADT film is mainly due to the increased area of crystal edges, which provides a diffusion pathway for gas molecules to arrive at the semiconductor‐dielectric interface.