This review aims to provide a technical roadmap and progress update for backplane thin film transistors (TFTs) used in organic light emitting diodes flat panel displays and next-generation flexible...

https://www.tandfonline.com/doi/pdf/10.1080/15980316.2020.1818641

Recent progress in the development of backplane thin film transistors for information displays

Resonant acceleration of plasma electrons in combined circularly polarized Gaussian laser fields and self-generated quasistatic fields has been investigated theoretically and numerically. The latter includes the radial quasistatic electric field, the azimuthal quasistatic magnetic field and the axial one. The resonant condition is theoretically given and numerically testified. The results show some of the resonant electrons are accelerated to velocities larger than the laser group velocity and thus gain high energy. For peak laser intensity I0 = 1 × 1020 W cm−2 and plasma density n0 = 0.1ncr, the relativistic electron beam with energies increased from 207 MeV to 262 MeV with a relative energy width around 24% and extreme low beam divergence less than 1° has been obtained. The effect of laser intensity and plasma density on the final energy gain of resonant electrons is also investigated.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263034608000086

Resonant acceleration of electrons by intense circularly polarized Gaussian laser pulses

Oxide semiconductors have been extensively studied as active channel layers of thin-film transistors (TFTs) for electronic applications. However, the field-effect mobility (μFE) of oxide TFTs is not sufficiently high to compete with that of low-temperature-processed polycrystalline-Si TFTs (50-100 cm2V-1s-1). Here, we propose a simple process to obtain high-performance TFTs, namely hydrogenated polycrystalline In2O3 (In2O3:H) TFTs grown via the low-temperature solid-phase crystallization (SPC) process. In2O3:H TFTs fabricated at 300 °C exhibit superior switching properties with µFE = 139.2 cm2V-1s-1, a subthreshold swing of 0.19 Vdec-1, and a threshold voltage of 0.2 V. The hydrogen introduced during sputter deposition plays an important role in enlarging the grain size and decreasing the subgap defects in SPC-prepared In2O3:H. The proposed method does not require any additional expensive equipment and/or change in the conventional oxide TFT fabrication process. We believe these SPC-grown In2O3:H TFTs have a great potential for use in future transparent or flexible electronics applications. 

/pdf/high-mobility-hydrogenated-polycrystalline-in2o3-in2o3-h-q1nrn9ye.pdf

High-mobility hydrogenated polycrystalline In2O3 (In2O3:H) thin-film transistors

/pdf/high-mobility-hydrogenated-polycrystalline-in2o3-in2o3-h-3i5et9jo.pdf

In this paper, the dynamic characteristics of electron acceleration by a chirped Gaussian laser pulse are studied regarding the synchronization between the axial force phase and electron. Linear, circular, and elliptical polarizations are employed in this investigation. It is found that the chirp parameter plays an important role in the phase synchronization procedure. In this numerical study, the accelerated electron could acquire several tens of GeV energies from a very intense chirped laser pulse. It is also found that the electron final energy is very sensitive to the state of the wave polarization.

Synchronization scheme in electron vacuum acceleration by a chirped Gaussian laser pulse

Amorphous In-Ga-Zn-O thin-film transistors on flexible substrates were prepared to investigate H2O adsorption under negative bias stress (NBS). Shorter channel lengths induce a more seriously deteriorated NBS stability due to the stronger electric field near the source or drain electrode. With increasing channel width, the NBS instability increases to a peak and then slightly decreases. Integrated Systems Engineering Technology Computer-aided Design (ISE-TCAD) simulation confirms that the electric field near the source/drain in the etch-stop layer is relatively dense, especially near the channel edges. The electric field direction is also confirmed to have significant effects on the H2O adsorption process.

H2O adsorption on amorphous In-Ga-Zn-O thin-film transistors under negative bias stress

Gallium-tin oxide (GTO) semiconductor thin films were prepared by spin-coating with 2-methoxyethanol as the solvent. Their crystal structures, optical transparency, chemical states and surface morphologies, along with the electrical properties, were dependent on Ga contents and annealing temperatures. The optimized GTO channel layer was applied in the high- k Al2O3 thin film transistor (TFT) with a low operation voltage of 2 V, a maximum field-effect mobility of 69 cm2 V−1 s−1, a subthreshold swing (SS) of 76 mV dec−1, a threshold voltage of 0.67 V and an on-off current ratio of 1.8×107. The solution-processed amorphous-GTO-TFTs would promote the development of low-consumption, low-cost and high performance In-free TFT devices.

/pdf/solution-processed-amorphous-gallium-tin-oxide-thin-film-for-59s0e2gyl2.pdf

Solution-processed amorphous gallium-tin oxide thin film for low-voltage, high-performance transistors

This paper presents the characteristics of vacuum laser acceleration in circularly polarized (CP) fields with the capture and acceleration scenario (CAS) scheme. Compared with linearly polarized laser fields, the main advantage for using a CP field is that its acceleration channel occupies a relatively larger phase space, stemming from the distribution of the longitudinal electric component, the dependence on the laser initial phase and on the incident polarization azimuth angle, etc. These features can give rise to greater acceleration efficiency. One of the disadvantages is the 'energy saturation' phenomenon if the laser intensity is sufficiently high, which comes from the additional Lorentz force component in the CP field. The output properties of the accelerated CAS electron bunch, such as the energy spectra, the angular distributions, the energy-angle correlations, the acceleration efficiency, the rms emittance and the energy divergence, are also examined. Physical explanations concerning these characteristics are presented.

Vacuum laser acceleration in circularly polarized fields

Concerning laser-driven electron acceleration in vacuum, a comparison was made between using circularly polarized (CP) laser field and linearly polarized (LP) field. It has been found that the main advantage for using CP field is that its acceleration channel occupies relatively larger phase space, which can give rise to greater acceleration efficiency. This feature chiefly comes from the difference in the distribution of the longitudinal electric components of these two kinds of fields. One of the disadvantages with CP field is the “energy saturation” phenomenon as the laser intensity is sufficiently high, resulting from the enhanced Lorentz force component in CP field. Physical explanations of these characteristics are addressed as well.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263034607000092

Dong Lin

Papers

H2O adsorption on amorphous In-Ga-Zn-O thin-film transistors under negative bias stress

Solution-processed amorphous gallium-tin oxide thin film for low-voltage, high-performance transistors

Vacuum laser acceleration in circularly polarized fields

Polarization effect of fields on vacuum laser acceleration

High‐Performance Thin‐Film Transistors with Nickel‐Doped Indium Zinc Oxide Channel Layers