A unified understanding of charge transport in organic semiconductors: the importance of attenuated delocalization for the carriers

Liu, Chuan,Huang, Kairong,Park, Won-Tae,Li, Minmin,Yang, Tengzhou,Liu, Xuying,Liang, Lijuan,Minari, Takeo,Noh, Yong-Young Royal Society of Chemistry 2017 Polymer Chemistry Vol.4 No.4

<▼1><P>The generalized Einstein relation (GER) can unify various theoretical models and predict charge transport in OSCs with various crystallinities, by altering the variance of the density of states and the delocalization degree in a Gaussian-distributed density of states.</P></▼1><▼2><P>The variety of charge transport theories for organic semiconductors (OSCs) raises the question of which models should be selected for each case, and there is a lack of generalized understanding regarding various OSCs over the full range of crystallinity from single crystal to amorphous. Here, we report that the generalized Einstein relation (GER) can unify various theoretical models and predict charge transport in OSCs with various crystallinities, by altering the variance of the density of states and the delocalization degree in a Gaussian-distributed density of states. The GER also provides a good fitting to much of the experimental data of temperature- and gate-voltage-dependent mobility for different OSCs in transistors. Consequently, disorders of charge transport in various OSCs can be directly compared in the same map, which reveals how energetic disorder and the delocalization degree determine charge transport in organic devices.</P></▼2>

Organic thin-film transistors with over 10 cm²/Vs mobility through low-temperature solution coating

Liu, Chuan,Liu, Xuying,Minari, Takeo,Kanehara, Masayuki,Noh, Yong-Young The Korean Infomation Display Society 2018 Journal of information display Vol.19 No.2

Recent studies on organic thin-film transistors (OTFTs) have reported high mobility values, but many of them showed non-ideal current-voltage characteristics that could lead to the overestimation of the mobility values. In this study, the non-ideal transistor behavior was briefly investigated by considering the effect of charge injection, and a method of overcoming the effect was developed. Correspondingly, various charge injection layers were developed, and their effects on the modification of metal contacts, including work function tuning and interfacial doping, were studied. The materials that had been coated formed a good metal-semiconductor interface through fine manipulation in the wetting and dewetting of the selected liquid. With such electrodes, the OTFTs were fabricated at room temperature and exhibited almost ideal transistor behavior in terms of the current-voltage characteristics, featuring high (over $10cm^2/Vs$) field-effect mobility.

Ultra-high-resolution printing of flexible organic thin-film transistors

Xuying Liu,Masayuki Kanehara,Chuan Liu,Takeo Minari 한국정보디스플레이학회 2017 Journal of information display Vol.18 No.2

Fully printed electronics on plastic have attracted considerable interest owing to their high compatibility and ease of integration. Here, an ultra-high-resolution printing technique based on parallel vacuum ultraviolet patterning that can produce high-contrast wettability regions on flexible substrates was developed. This technique was used to selectively deposit a functional ink with a 1μm feature size, thereby allowing the large-scale fabrication of organic thin-film transistors with channels as short as 1μm under an ambient atmosphere. Moreover, in short-channel devices, hole injection barriers can be tuned by printing the optimum gate overlaps associated with selectively doping semiconductor/electrode interfaces, resulting in a marked reduction in contact resistance from 20 to 1.5, and an elevation of the charge carrier mobility to a record high of 0.3 cm2 V−1 s−1 in a 1-μm-channel device. The results indicate that the developed technique is promising for the fabrication of large-area, high-resolution, low-cost electronics.

Organic thin-film transistors with over 10 cm2/Vs mobility through low-temperature solution coating

Chuan Liu,Xuying Liu,Takeo Minari,Masayuki Kanehara,노용영 한국정보디스플레이학회 2018 Journal of information display Vol.19 No.2

Recent studies on organic thin-film transistors (OTFTs) have reported high mobility values, but many of them showed non-ideal current–voltage characteristics that could lead to the overestimation of the mobility values. In this study, the non-ideal transistor behavior was briefly investigated by considering the effect of charge injection, and a method of overcoming the effect was developed. Correspondingly, various charge injection layers were developed, and their effects on the modification of metal contacts, including work function tuning and interfacial doping, were studied. The materials that had been coated formed a good metal-semiconductor interface through fine manipulation in the wetting and dewetting of the selected liquid. With such electrodes, the OTFTs were fabricated at room temperature and exhibited almost ideal transistor behavior in terms of the current–voltage characteristics, featuring high (over 10 cm2/Vs) field-effect mobility.

Curcumin Alleviates the Side Effects of Cisplatin on Gastric Emptying of Mice by Inhibiting the Signal Changes of Acetylcholine and Interstitial Cells of Cajal

Hui Li,Wenhua Xu,Xuying Liu,Junli Ye,Peijie Li,Fangfang Shang,Xiaoling Yu 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.9

Cisplatin is a widely used anticancer drug that has adverse effects on gastrointestinal function. Curcumin is a natural polyphenol extracted from the rhizome of turmeric that has a wide range of biological activities. The present study investigated the effects of cisplatin on gastric emptying in mice and examined whether these can be inhibited by curcumin. We found that pretreatment with curcumin (200 mg/kg/day) for 10–30 days partly inhibited the decreases in gastric emptying rate and body weight induced by cisplatin. Furthermore, cisplatin reduced acetylcholine (ACh) concentration and the messenger RNA (mRNA) level of ACh receptor (AChR) as well as acetylcholinesterase activity in the stomach of mice; caused ultrastructural damage to interstitial cells of Cajal (ICC); and altered the expression of c-kit/stem cell factor and the gap junction protein connexin 43 in ICC. Curcumin pretreatment inhibited the effects of cisplatin on ACh indicators and ICC. These results demonstrate that curcumin can protect against cisplatin-induced gastric emptying disorder and thus has therapeutic potential for alleviating this condition in cancer patients receiving cisplatin chemotherapy.

Diffusion mechanism of deep shale gas and its carbon isotope fractionation: a combined simulated and mathematical analysis

Yu Zou,Guojian Wang,Cheng Tao,Rui Zhou,Shangqing Zhang,Dongna Liu,Xiaohui Lin,Xuying Zheng 한국지질과학협의회 2023 Geosciences Journal Vol.27 No.3

Unlike the release pressure process in shale gas exploitation, in this study, the concentration diffusion process is deeply discussed under constant temperature-pressure conditions, which aims to evaluate the preservation conditions of shale gas reservoirs in combination with isotopic fractionation characteristics. The isobaric diffusion experiment emphasized that decreasing pressure can lead to enhanced diffusion and isotope fractionation. The established mathematical model not only confirms the results of the simulating experiment, but also suggests that the contributions of Fick, Knudsen and surface diffusion to the migration of methane (including 12CH4 and 13CH4) vary in the geological evolution of shale reservoirs, which are mainly controlled by the pore system and gas pressure. Based on the analysis of specific samples of Longmaxi shale (r = 11.7 nm) and Niutitang shale (r = 1.3 nm), we propose that: 1) high pressure condition (> 20 MPa) can significantly limit Knudsen diffusion, which is the reason for reducing the total diffusion coefficient (DTotal) and isotope fractionation, while low pressure (< 10 MPa) and small pore radius (ca. 1 nm) can strengthen the fractionation; 2) pore connectivity and heterogeneity can lead to an order of magnitude change in DTotal, while the influence of temperature is relatively small. According to the mathematical model, it can be expected that enhanced dissipation intensity and isotope fractionation of shale gas may occur in the process of basin uplift and pressure relief, which can potentially be used for the evaluation of reservoir preservation.