Polymer field-effect transistors operated in the n-channel model with a top-gate/bottom-contact are processed using a solution method. The transistor performance depends on the gate dielectric layer. A high performanc...Polymer field-effect transistors operated in the n-channel model with a top-gate/bottom-contact are processed using a solution method. The transistor performance depends on the gate dielectric layer. A high performance polymer transistor is achieved, with the saturated electron mobility of about 0.46cm2/Vs, threshold voltage nearly 0 V and subthreshold sway of about 0.9 V/decade, employing a polystyrene (PS) dielectric layer. The transistor performances are further improved with increasing current and lower operation voltages by utilizing a bi-layer gate dielectric, comprising a thin PS dielectric layer adjacent to the semiconductor to minimize the density of the interface traps for obtaining a small VT, a large μ and a poly(methyl methacrylate) (PMMA) dielectric layer with a relatively high-k adjacent to the gate electrode for enlarging the capacitance, processed from the orthogonal solvents.展开更多
Dielectric relaxation spectroscopy(DRS) of poly(ε-caprolactone) with different draw ratios showed that the mobility of polymer chains in the amorphous part decreases as the draw ratio increases. The activation en...Dielectric relaxation spectroscopy(DRS) of poly(ε-caprolactone) with different draw ratios showed that the mobility of polymer chains in the amorphous part decreases as the draw ratio increases. The activation energy of the α process, which corresponds to the dynamic glass transition, increases upon drawing. The enlarged gap between the activation energies of the α process and the β process results in a change of continuity at the crossover between the high temperature a process and the α and β processes. At low drawing ratios the a process connects with the β process, while at the highest drawing ratio in our measurements, the a process is continuous with the αprocess. This is consistent with X-ray diffraction results that indicate that upon drawing the polymer chains in the amorphous part align and densify upon drawing. As the draw ratio increases, the α relaxation broadens and decreases its intensity, indicating an increasing heterogeneity. We observed slope changes in the α traces, when the temperature decreases below that at which τα≈ 1 s. This may indicate the glass transition from the ‘rubbery' state to the non-equilibrium glassy state.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 61177028
文摘Polymer field-effect transistors operated in the n-channel model with a top-gate/bottom-contact are processed using a solution method. The transistor performance depends on the gate dielectric layer. A high performance polymer transistor is achieved, with the saturated electron mobility of about 0.46cm2/Vs, threshold voltage nearly 0 V and subthreshold sway of about 0.9 V/decade, employing a polystyrene (PS) dielectric layer. The transistor performances are further improved with increasing current and lower operation voltages by utilizing a bi-layer gate dielectric, comprising a thin PS dielectric layer adjacent to the semiconductor to minimize the density of the interface traps for obtaining a small VT, a large μ and a poly(methyl methacrylate) (PMMA) dielectric layer with a relatively high-k adjacent to the gate electrode for enlarging the capacitance, processed from the orthogonal solvents.
基金the research programme of the Dutch Polymer Institute (DPI),project#623
文摘Dielectric relaxation spectroscopy(DRS) of poly(ε-caprolactone) with different draw ratios showed that the mobility of polymer chains in the amorphous part decreases as the draw ratio increases. The activation energy of the α process, which corresponds to the dynamic glass transition, increases upon drawing. The enlarged gap between the activation energies of the α process and the β process results in a change of continuity at the crossover between the high temperature a process and the α and β processes. At low drawing ratios the a process connects with the β process, while at the highest drawing ratio in our measurements, the a process is continuous with the αprocess. This is consistent with X-ray diffraction results that indicate that upon drawing the polymer chains in the amorphous part align and densify upon drawing. As the draw ratio increases, the α relaxation broadens and decreases its intensity, indicating an increasing heterogeneity. We observed slope changes in the α traces, when the temperature decreases below that at which τα≈ 1 s. This may indicate the glass transition from the ‘rubbery' state to the non-equilibrium glassy state.