Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userFunctionalized pentacene field-effect transistors with logic circuit applications
65
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Funtionalized pentacene, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene), field-effect transistors(FETs) were made by thermal evaporation or solution deposition method and the mobility was measured as a function of temperature and light power. The field-effect mobility ($mu$$_{rm FET}$) has a gate-voltage dependent activation energy. A non-monotonic temperature dependence was observed at high gate voltage (V$_G$ $<$ -30 V) with activation energy E$_a$ $sim$ 60 - 170 meV,depending on the fabrication procedure. The gate-voltage dependent mobility and non-monotonic temperature dependence indicates that shallow traps play important role in the transport of TIPS-pentacene films. The current in the saturation regime as well as mobility increase upon light illumination and is proportional to the light intensity, mainly due to the photoconductive response. Transistors with submicron channel length showed unsaturating current-voltage characteristics due to the short channel effect. Realization of simple circuits such as NOT(inverter), NOR, and NAND logic gates are demonstrated for thin film TIPS-pentacene transistors.
rate research
Read More
We report on the generation of a discrete trap state during negative gate bias stress in pentacene single crystal flip-crystal field-effect transistors with a SiO2 gate dielectric. Trap densities of up to 2*10^12 cm^-2 were created in the experiments. Trap formation and trap relaxation are distinctly different above and below ~280 K. In devices in which a self-assembled monolayer on top of the SiO2 provides a hydrophobic insulator surface we do not observe trap formation. These results indicate the microscopic cause of the trap state to be water adsorbed on the SiO2 surface.
We show herein fabrication and field-modulated thermopower for KTaO3 single-crystal based field-effect transistors (FETs). The KTaO3 FET exhibits field effect mobility of ~8 cm2/Vs, which is ~4 times larger than that of SrTiO3 FETs. The thermopower of the KTaO3 FET decreased from 600 to 220 microV/K by the application of gate electric field up to 1.5 MV/cm, ~400 microV/K below that of an SrTiO3 FET, clearly reflecting the smaller carrier effective mass of KTaO3.
Magnetic skyrmions are of considerable interest for low-power memory and logic devices because of high speed at low current and high stability due to topological protection. We propose a skyrmion field-effect transistor based on a gate-controlled Dzyaloshinskii-Moriya interaction. A key working principle of the proposed skyrmion field-effect transistor is a large transverse motion of skyrmion, caused by an effective equilibrium damping-like spin-orbit torque due to spatially inhomogeneous Dzyaloshinskii-Moriya interaction. This large transverse motion can be categorized as the skyrmion Hall effect, but has been unrecognized previously. The propose device is capable of multi-bit operation and Boolean functions, and thus is expected to serve as a low-power logic device based on the magnetic solitons.
Pentacenequinone (PnQ) impurities have been introduced into a pentacene source material at number densities from 0.001 to 0.474 to quantify the relative effects of impurity content and grain boundary structure on transport in pentacene thin-film transistors. Atomic force microscopy (AFM) and electrical measurements of top-contact pentacene thin-film transistors have been employed to directly correlate initial structure and final film structures, with the device mobility as a function of added impurity content. The results reveal a factor four decrease in mobility without significant changes in film morphology for source PnQ number fractions below ~0.008. For these low concentrations, the impurity thus directly influences transport, either as homogeneously distributed defects or by concentration at the otherwise-unchanged grain boundaries. For larger impurity concentrations, the continuing strong decrease in mobility is correlated with decreasing grain size, indicating an impurity-induced increase in the nucleation of grains during early stages of film growth.
We have measured the interlayer and in-plane (needle axis) thermal diffusivities of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn). The needle axis value is comparable to the phonon thermal conductivities of quasi-one dimensional organic metals with excellent pi-orbital overlap, and its value suggests that a significant fraction of heat is carried by optical phonons. Furthermore, the interlayer (c-axis) thermal diffusivity is at least an order of magnitude larger, and this unusual anisotropy implies very strong dispersion of optical modes in the interlayer direction, presumably due to interactions between the silyl-containing side groups. Similar values for both in-plane and interlayer diffusivities have been observed for several other functionalized pentacene semiconductors with related structures.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
