Defect-engineered colossal permittivity with controlled dielectric loss in BaTiO 3 ceramics via particle hydroxylation through wet chemical synthesis.

Abstract Metal‐oxide thin‐film transistors (TFTs) have garnered much attention because of their advantages such as high transparency, low leakage current, and low processing temperature. However, there is a need to continuously improve their mobility and bias stability for application to next‐generation advanced electronics. In this study, the thickness of bilayer semiconductors is finely controlled to enhance the charge transport characteristics and bias stability in solution‐processed heterojunction oxide TFTs. The thicknesses of the top and bottom layers in the bilayer are individually adjusted by controlling solution molarity. The introduction of a bilayer channel improved the electrical performance of oxide TFTs via effective charge transport. However, trap‐limited conduction becomes dominant in the bilayer with an excessively thick top layer, thereby leading to a significant reduction in mobility and positive bias stability. Meanwhile, although increasing the bottom layer thickness contributes to improved mobility and reliability, it causes a serious negative shift in threshold voltage (V TH ). TFTs with an optimized bilayer structure show high mobility at a V TH close to 0 V and have particularly excellent positive bias stress stability. This study on bilayer channel thickness will be beneficial for developing advanced transistors with optimized bilayer or multilayer channels.

Defect-engineered colossal permittivity with controlled dielectric loss in BaTiO 3 ceramics via particle hydroxylation through wet chemical synthesis.

Abstract Metal‐oxide thin‐film transistors (TFTs) have garnered much attention because of their advantages such as high transparency, low leakage current, and low processing temperature. However, there is a need to continuously improve their mobility and bias stability for application to next‐generation advanced electronics. In this study, the thickness of bilayer semiconductors is finely controlled to enhance the charge transport characteristics and bias stability in solution‐processed heterojunction oxide TFTs. The thicknesses of the top and bottom layers in the bilayer are individually adjusted by controlling solution molarity. The introduction of a bilayer channel improved the electrical performance of oxide TFTs via effective charge transport. However, trap‐limited conduction becomes dominant in the bilayer with an excessively thick top layer, thereby leading to a significant reduction in mobility and positive bias stability. Meanwhile, although increasing the bottom layer thickness contributes to improved mobility and reliability, it causes a serious negative shift in threshold voltage (V TH ). TFTs with an optimized bilayer structure show high mobility at a V TH close to 0 V and have particularly excellent positive bias stress stability. This study on bilayer channel thickness will be beneficial for developing advanced transistors with optimized bilayer or multilayer channels.

In this study, selective photo-oxidation (SPO) is proposed as a simple, fast, and scalable one-stop strategy that enables simultaneous self-patterning and sensitivity adjustment of ultrathin stretchable strain sensors. The SPO of an elastic substrate through irradiation time-controlled ultraviolet treatment in a confined region enables precise tuning of both the surface energy and the elastic modulus. SPO induces the hydrophilization of the substrate, thereby allowing the self-patterning of silver nanowires (AgNWs). In addition, it promotes the formation of nonpermanent microcracks of AgNWs/elastomer nanocomposites under the action of strain by increasing the elastic modulus. This effect improves sensor sensitivity by suppressing the charge transport pathway. Consequently, AgNWs are directly patterned with a width of 100 μm or less on the elastic substrate, and AgNWs/elastomer-based ultrathin and stretchable strain sensors with controlled sensitivity work reliably in various operating frequencies and cyclic stretching. Sensitivity-controlled strain sensors successfully detect both small and large movements of the human hand.

). The threshold voltage shift under positive bias stress was 1.70 V, which demonstrates excellent bias stability. These results show that simultaneous high-temperature annealing of the channel and CL is essential to reduce trap-assisted scattering and stabilize electrostatics in JL TFTs, providing practical process guidelines for bias-stable and high-performance oxide electronics.

This study fabricated double-gate (DG) amorphous indium-gallium–zinc oxide (a-IGZO) thin-film transistors (TFTs) and consequently assessed their characteristics in both bottom gate-top gate connection (BTC) and bottom gate-source connection (BSC) modes to improve the performance of active-matrix organic light-emitting diode (AMOLED) displays. The BTC mode exhibited a subthreshold swing (SS) of 84.4 mV/dec, demonstrating superior switching performance, whereas the BSC mode showed a relatively lower characteristic at 199.9 mV/dec. It is well known that low SS is beneficial for TFT switches. However, this article demonstrates that a TFT with low SS is disadvantageous for threshold voltage compensation in pixel circuits. To investigate the effect of the electrical characteristics of DG a-IGZO TFTs on the compensation quality of OLED displays, simulations were conducted via the application of each BG connection mode to the driving TFT ( $T_{\text{DR}}$ ) within a circuit comprising four nMOS TFTs and two capacitors. The compensation performance was evaluated based on the variations in $V_{\text{TH}}$ . In the BTC mode, when the $V_{\text{TH}}$ variation ( $\Delta V_{\text{TH}}$ ) of $T_{\text{DR}}$ was −0.5 V, the pixel current variation (PCV) was 133.6%. By contrast, in the BSC mode, the PCV was significantly lower 18.6%, demonstrating superior compensation quality.