The hole carrier field-effect mobility of hybrid molybdenum disulfide (MoS2) nanoparticles suspended in poly(3-hexylthiophene) (P3HT) thin film transistor (TFT) was found to be enhanced when it compared to P3HT-only TFTs. The improvement in the hole charge transport was found to be a function of the concentration of MoS2 in P3HT with high MoS2 concentrations resulting in an increase in the on-current of the device. Moreover, Au has a high work function of 5.1 eV which is
suitable with the HOMO level of P3HT. We find that MoS2 and
Au have the proper energy level for hole transport and injection.
We demonstrate an electrically induced, non-volatile, metal-insulator phase transition in a MoS$_2$ transistor. A single crystalline, epitaxially grown, PbZr$_{0.2}$Ti$_{0.8}$O$_3$ (PZT) was placed in the gate of a field effect transistor made of thin film MoS$_2$. When a gate voltage is applied to this ferroelectric gated transistor, a clear transition from insulator to metal and vice versa is observed. Importantly, when the gate voltage is turned off, the remnant polarization in the ferroelectric can keep the MoS$_2$ in its original phase, thereby providing a non-volatile state. Thus a metal…
High sensitivity MEMS pressure sensor chip for different ranges (1 to 60 kPa) utilizing the novel electrical circuit of piezosensitive differential amplifier with negative feedback loop (PDA-NFL) is developed. Pressure sensor chip PDA-NFL utilizes two bipolar-junction transistors (BJT) with vertical n-p-n type structure (V-NPN) and eight piezoresistors (p-type). Both theoretical model of sensor response to pressure and temperature and experimental data are presented. Data confirms the applicability of theoretical model. Introduction of the amplifier allows for decreasing chip size while keepin…
Organic water-gated thin-film transistors (WG-TFTs) are of great interest in developing low-cost and high-performance biosensors. The device's sensitivity to changes in measurement conditions can impair long-term operation, and care must be taken to ensure that the WG-TFT sensor response is due to an actual biorecognition event occurring on the sensing electrode. This work aims to clarify the long-term stability of a poly-3-hexylthiophene (P3HT) WG-TFT operated intermittently over two months during 5750 measurement cycles. We have evaluated the device figures of merit (FOM), such as threshold …
We report, for CVD-grown monolayer MoS2, the very first results on temporal degradation of material and device performance under electrical stress. Both low and high field regimes of operation are explored at different temperatures, gate bias and stress cycles. During low field operation, current is found to saturate after hundreds of seconds of operation with the current decay time constant being a function of temperature and stress cycle. Current saturation after several seconds during low field operation occurs when a thermal equilibrium is established. However, high field operation, especi…
We have measured both the current-voltage ($I_\mathrm{SD}$-$V_\mathrm{GS}$) and capacitance-voltage ($C$-$V_\mathrm{GS}$) characteristics of a $\mathrm{MoS_2-LiNbO_3}$ field effect transistor. From the measured capacitance we calculate the electron surface density and show that its gate voltage dependence follows the theoretical prediction resulting from the two-dimensional free electron model. This model allows us to fit the measured $I_\mathrm{SD}$-$V_\mathrm{GS}$ characteristics over the \emph{entire range} of $V_\mathrm{GS}$. Combining this experimental result with the measured current-vol…
Here, in an effort towards facile and fast screening/diagnosis of novel coronavirus disease 2019 (COVID-19), we combined the unprecedently sensitive graphene field-effect transistor (Gr-FET) with highly selective antibody-antigen interaction to develop a coronavirus immunosensor. The Gr-FET immunosensors can rapidly identify (about 2 mins) and accurately capture the COVID-19 spike protein S1 (which contains a receptor binding domain, RBD) at a limit of detection down to 0.2 pM, in a real-time and label-free manner. Further results ensure that the Gr-FET immunosensors can be promisingly applied…
Thin-film transistors (TFTs) represent a wide-spread tool to determine the charge-carrier mobility of materials. Mobilities and further transistor parameters like contact resistances are commonly extracted from the electrical characteristics. However, the trust in such extracted parameters is limited, because their values depend on the extraction technique and on the underlying transistor model. We propose a technique to establish whether a chosen model is adequate to represent the transistor operation. This two-step technique analyzes the electrical measurements of a series of TFTs with diffe…
A Comprehensive Study of Charge-Carrier Mobility in Double Lateral-Gate Silicon Junctionless Transistors
Laye Rooyan Part, Isfahan Science and Technology Town（拉耶鲁扬部分，伊斯法罕科技城）；Department of Physics, Isfahan University of Technology（伊斯法罕理工大学物理系）；Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia（马来西亚国立大学微工程与纳米电子研究所）；Department of Electrical and Computer Engineering, University of Texas at Dallas（德克萨斯大学达拉斯分校电气与计算机工程系）
Here, we propose a Charge Plasma (CP)-based Germanium Double Gate Tunnel Field-Effect Transistor (Ge-DGTFET) device structure, where a CP is induced in the heavily doped source region using the work function engineering of source electrode. The CP enables creation of electrical metallurgical junction and converts n-p-n to p-n-p-n structure of TFET and enhances the drain current, reliability, eliminate additional pocket ion-implantation. The proposed CP-Ge-DGTFET device structure revealed excellent electrical DC performance as compared to the conventional Ge-DGTFET device structure such as high…
Solution processed polymers are at the core of organic electronics. Polyradicals (polymers in which each repeating unit contains an unpaired spin) are unique alternatives to their p-conjugated, semiconducting counterparts. Unique of polyradicals are tunable charge states localized at their repeating units, which enable electrically switchable charge transport regimes. Tremendous efforts were focused on polyradical memristors and batteries. Notwithstanding recent progress in doping, polyradical field-effect transistors (PR-FETs) have not been reported. Here, we show that vertical architectures,…
We study the electrical transport in back-gate field-effect transistors with ultrathin palladium diselenide (PdSe2) channel. The devices are normally-on and exhibit dominant n-type conduction at low pressure. The electron conduction, combined with the sharp edge and the workfunction decreasing with the number of layers, opens the way to applications of PdSe2 nanosheets in vacuum electronics. In this work, we demonstrate field emission from few-layer PdSe2 nanosheets with current up to the uA and turn-on field below 100 V/um, thus extending the plethora of applications of this recently isolated…
Trion Engineered Multimodal Transistors in Two dimensional Bilayer Semiconductor Lateral Heterostructures
Indian Institute of Technology Kharagpur（印度理工学院卡拉格普尔分校）；Indian Institute of Technology Bombay（印度理工学院孟买分校）；Philipps-University at Marburg（马尔堡菲利普斯大学）；Chalmers University of Technology（查尔姆斯理工大学）
In this paper, we investigated the performance of thin-film transistors (TFTs) with different channel configurations including single-active-layer (SAL) Sn-Zn-O (TZO), dual-active-layers (DAL) In-Sn-O (ITO)/TZO, and triple-active-layers (TAL) TZO/ITO/TZO. The TAL TFTs were found to combine the advantages of SAL TFTs (a low off-state current) and DAL TFTs (a high mobility and a low threshold voltage). The proposed TAL TFTs exhibit superior electrical performance, e.g. a high on-off state current ratio of 2*10^8, a low threshold voltage of 0.52 V, a high saturation mobility of 145.2 cm2/Vs, and …
Organic semiconductors are usually not thought to show outstanding performance in highly-integrated, sub 100 nm transistors. Consequently, single-crystalline materials such as SWCNTs, MoS2 or inorganic semiconductors are the material of choice at these nanoscopic dimensions. Here, we show that using a novel vertical field-effect transistor design with a channel length of only 40 nm and a footprint of 2 x 80 x 80 nm$^2$, high electrical performance with organic polymers can be realized when using electrolyte gating. Our organic transistors combine high on-state current densities of above 3 MA/c…
We develop an InAs nanowire gate-all-around field-effect transistor using a transparent conductive zinc oxide (ZnO) gate electrode, which is in-situ atomic layer deposited after growth of gate insulator of Al2O3. We perform magneto-transport measurements and find a crossover from weak localization to weak antilocalization effect with increasing gate voltage, which demonstrates that the Rashba spin-orbit coupling is tuned by the gate electrode. The efficiency of the gate tuning of the spin-orbit interaction is higher than those obtained for two-dimensional electron gas, and as high as that for …
