Thin-Film Transistors

In article number 1900832 by Shijie Zhan, Bo Hou, and co-workers, a parylene-C/AlO_x hybrid passivation approach is introduced to reduce the damage during AlO_x atomic layer deposition. This method enables a flexible transistor backplane matrix with remarkably improved bias stability.

The effect of the ZnO/WO₃ molar ratio on the response of ZnO/WO₃ composite nanoparticle sensors to CO is investigated. The strongest response to 200 ppm CO is obtained by the 6:4 ZnO/WO₃ composite sensor in this study, whereas a 5:5 ZnO/WO₃ composite sensor showed the strongest response to gases in previous reports.

The intermediate temperature T* of Pb[(Zn_1/3Nb_2/3)_1–xTi_x]O₃ single crystals is investigated using Brillouin spectroscopy. The temperatures of the steepest descent of the half width of the longitudinal acoustic mode are nearly the same irrespective of composition, revealing universal feature of T* at which dynamic polar nanoregions are transformed into quasistatic ones.

A parylene-C and aluminum oxide (AlO_x) hybrid passivation approach are introduced to reduce the damage during AlO_x atomic layer deposition. Based on Mott–Schottky and X-ray diffraction characterizations, the thin-film transistor (TFT) performance enhancement is attributed to doping density variation that results in high-performance depletion-mode indium–zinc–gallium–oxide TFT matrix to be operated on polyethylene naphthalate substrate with enhanced bias stability.

When the ZnO nanorods are grown using the hydrothermal method, interstitial oxygens are generated in the ZnO lattice. So, the decrease of the number of defects is necessary. Herein, the number of interstitial oxygens using thermal annealing is reduced, and it led to the improvement in the crystallinity and photosensitivity of ZnO nanorods compared with nonannealed ZnO nanorods.

Amorphous SiInZnO thin films are fabricated according to the Si content, and their electrical properties are analyzed under various measurement conditions. It is confirmed that the nonideal transfer characteristics, at low V_ds, may be caused by the bandgap changes. For the next generation of low-power devices, the bandgap between the electrode and the semiconductors requires consideration.

Specific heat, dielectric properties, and domain structure studies in antiferroelectric PbHf_1−xSn_xO₃ single crystals with three different concentrations (x = 0.08, 0.1, 0.23) are performed in function of temperature. Temperature- and composition (concentration of Sn ions)-induced phase transitions (PTs) are further investigated by Brillouin light scattering spectroscopy to deeply understand the dynamics of PTs in relation to domain structure and physical properties.

The crossbar array memristor with a structure of Al/three-multi-stacked indium zinc oxide/TiO₂/Al exhibits uniformity and reproducibility of resistance switching behavior with low-resistance state and high-resistance state voltage sweeps, and show excellent retention performance over 2 × 10³s. This research suggested that some other appropriate metal oxide thin films with good resistive switching performance can be used to prepare structurally enhanced memristor devices.

Co or Ni encapsulated in the carbon nanotubes [CNT@(Co or Ni)] was obtained via calcination of Co- and Ni-ZIF-67. The porous CNT@(Co or Ni) exhibits superior electrochemical performance when used as a cathode material for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER).

Pb-free 0.65Bi_1.05FeO₃–0.35BaTiO₃ (BF–35BT) piezoceramics are synthesized via conventional solid-state reaction by varying sintering dwell time (t_s) to study its effect on electromechanical properties. t_s has a profound effect on grain size and density of composition, showing that for t_s = 3 h, enhanced electromechanical properties are achieved with a maximum relative density of 96.61% and grain size of 5.41 μm.

Herein, it is demonstrated that boron-doped diamond layer is grown on freestanding heteroepitaxial diamond substrates by microwave plasma chemical vapor deposition (MPCVD) to verify the high potential of large-size heteroepitaxial diamond as an ultimate semiconductor material.

Herein, amorphous SiZnSnO (a-SZTO) thin-film transistors (TFTs) are fabricated and analyzed according to the oxygen partial pressure [p(O₂)] ratio. The V_th moves to positive direction, as the p(O₂) increases. In the inverter, the V_tr moves to positive direction as the p(O₂) increases. It is possible to control the V_tr of n-type only inverter.

The substitution of Fe³⁺ into the Ti⁴⁺ sites leads to the oxygen vacancies formation, which can cause the lattice distortion. Excellent ferroelectric properties (P_r ≈ 26.8 μC cm⁻², E_c ≈ 20.4 kV cm⁻¹) and the highest normalized strain ($d_{33}^{*}$) of 386 pm V⁻¹ are obtained in Bi_0.5(Na_0.68K_0.22Li_0.10)_0.5Ti_0.99Fe_0.01O₃ ceramic; the morphotropic phase boundary (MPB) composition where rhombohedral and tetragonal phases coexist with 51.3:48.7% ratio.

(1−x)Bi_0.97Sm_0.08FeO₃−xBaTiO₃ ceramics (with x = 0.00–0.05) are synthesized through the conventional solid-state reaction method. The remanent polarizaion of the furance cooled ceramic significantly enhances from 12 to 28.5 μC cm⁻² with water quenching and BaTiO₃ addition. High piezoelectric performace (d₃₃ = 56 pC N⁻¹ and d₃₃^* = 40 pm V⁻¹) obatins for an optimum composition (with x = 0.03).

Nanosecond laser annealing is performed on in situ phosphorus-doped silicon in single- and multipulse modes. The active phosphorus concentration is increased with the laser power density and number of laser pulses and more phosphorus is activated with nanosecond lasers than with millisecond lasers. Moreover, almost all the incorporated phosphorus atoms are activated.

Comparison of the strain properties of phosphorus doped silicon formed by phosphorus implanted and in situ phosphorus-doped. The same level of strain is applied regardless of the doping method. This implies that phosphorus acting as a stressor is present, suggesting that stress can also be applied through the phosphorus implantation with laser spike annealing treatment to suppress diffusion.

In situ phosphorus-doped (ISPD) silicon layer are epitaxially grown on silicon (100) and (111) substrates. The ISPD layer on the (111) silicon substrate exhibits more defects and they induce strain relaxation. Atomic resolution energy-dispersive X-ray spectroscopy (EDX) mapping results in a higher concentration of phosphorus at defects.

The thermolytic deposition is investigated for a large scale and direct synthesis of a MoS₂ nanolayer on micro-pyramidal p-Si wafers for solar cell application. The MoS₂ nanolayer shows a transition from an amorphous to a crystalline phase after the annealing process. The MoS₂ based heterostructures in p-Si photovoltaic devices produce the photoconversion efficiencies of up to 11.47%.

The hollow structure of tin oxide (SnO₂) is synthesized without a template. The synthesis of the core-shell structure forms the heterojunction between SnO₂ and zinc oxide (ZnO). The junction between SnO₂ and ZnO changes the charge transfer and interfacial effects on the surface of the material. This structure can be applied to the field of gas sensors and photocatalysts.

Herein, the efficient energy conversion of microwave annealing (MWA) on the electrical properties of rare metal-free zinc–tin oxide (ZTO) thin-film transistors (TFTs) is evaluated. Furthermore, the instabilities of gate bias temperature stress are also investigated. Compared with zinc oxide TFTs and furnace thermal-annealed devices, MWA-treated ZTO TFTs exhibit highly improved electrical and stability characteristics.

The magnetic properties of selected metal–organic frameworks (MOFs) are assessed using alternating current (AC)/direct current (DC) magnetic susceptibility and field-dependent magnetization. The magnetic state of the MOF-74-M (M = Fe, Co, Ni) studied can be changed from ferromagnetic or antiferromagnetic to superparamagnetic. These materials can be used for novel industrial applications in the field of molecular spintronics.

Anisotropic carrier transport in organic luminescent polymer semiconductor thin film is directly visualized using real-time photoluminescence (PL) decay imaging. Difference in the mobility anisotropy for hole and electron is clearly observed. That is attributed to the difference in the electron distribution in the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels.

Ni-based 1D coordination polymer Ni-DAB derived from 3,3′-diaminobenzidine ligand is shown to be a stable and fast anode material for potassium batteries operating in the safe voltage window of 0.4–2.0 V versus K⁺/K. Capacity of 158 mA h g⁻¹ is delivered by Ni-DAB at 1 A g⁻¹, whereas the capacity fade is only 8.6% after 600 cycles.

Without the use of any buffer layer, vertically oriented trilayer MoS₂ nanoflakes are grown on-chip by chemical vapor deposition method for room-temperature NO₂ gas sensor application. Taking advantages of the vertically aligned nanoflakes, the NO₂ gas is adsorbed on both sides of the nanoflakes, thus significantly enhancing the gas sensing performance of the sensor.

Two simple redox-active naphthalene diimide derivatives bearing sulfonic and carboxylic groups in the form of potassium salts are synthesized. Promising specific capacity of 86–96 mAh g⁻¹ in combination with average cell discharge potentials of ≈2.2 V is achieved, thus featuring these compounds as cheap and scalable cathode materials for potassium batteries designed for stationary energy storage applications.