Amorphous oxide semiconductor thin‐film transistors (AOS TFTs) have shown significant potential in the applications of increasingly advanced transparent and flexible electronic devices, where high speed, high transparency, and low power consumption are highly demanded. Yet, typical back‐channel etch (BCE) configuration used in the majority of TFTs still suffers from poor gate controllability, severe electrical field dispersion, relatively large parasitic capacitance and contact resistance. Here, a new embedded structure for TFTs with self‐alignment and even simpler fabrication process, outperforming conventional BCE counterpart in above aspects, is proposed in this work. More concentrated electrical field, improved gate control ability accompanied with lower contact resistance are achieved in the embedded TFTs. Consequently, superior electrical characteristics with subthreshold swing of 106.7 mV dec−1 and mobility as high as 32.10 cm2 V−1 s−1 are obtained. In addition, leakage current as well as contact resistance evidently decline compared to that in traditional BCE TFTs. By the assistance of Silvaco TCAD simulation, the performance and mechanism behind are cross‐validated from another perspective. Overall, such embedded configuration has equipped TFTs with appealing performance and it is also possible to enable other devices exploiting such structure with new possibility and thus a broader application.

The advanced field of bioelectronics bridges the electronic world and biological systems, opening a new area for More than Moore and stirring a wave of exploration in biomaterials. However, previously reported biomaterials usually suffer from poor purity and inferior electro-optic performance, discouraging their further development in bioelectronics. Here, porcine collagen extracted from pigskin through supercritical carbon dioxide is utilized as a dielectric layer in capacitors. A protein-amicable and low-temperature supercritical fluid (LT-SCF) strategy is also explored to enhance the electro-optic figure of merits. With the assistance of supercritical CO 2 fluids, free amino acids that might have a detrimental effect on the electro-optic performance of the devices have been eliminated. After LT-SCF, the electrical characteristics involving current−voltage and capacitance−voltage become more stable. The leakage currents of capacitors treated with LT-SCF drop by 15 times. The capacitance and conductance also have declining tendencies, contributing to reduced power consumption. Regarding optical characteristics, transparency and refractive index are also substantially enhanced. And numerous material analyses further verify the role of supercritical CO 2 fluids. More notably, the biodegradability of collagen films can be achieved with fast water dissolution. Overall, this low-temperature and protein-amicable supercritical fluid technology brings endless possibilities to explore collagen-based bioelectronics.

Poly(vinyl alcohol) (PVA) emerges as a promising sustainable material for environmentally friendly electronics, because of its biodegradable and biocompatible properties. Unfortunately, PVA suffers from problems associated with large leakage current, poor stability, and insufficient transparency. Impurities, particularly those related to sodium, are the major cause of the poor electric-optical characteristics when PVA acts as dielectric layer or substrate. However, removal of sodiumassociated impurities has been one of the daunting challenges.Here, an ecofriendly supercritical carbon dioxide (SCCO 2 )assisted hydration (SAH) strategy is introduced to eliminate the deep-seated sodium-related impurities. Ultrapurified PVA is obtained with outstanding insulation and high transmittance via a room-temperature SAH process, resulting in a 100-fold reduction in leakage, better stability, and up to 98% transparency in PVA-based devices. The SAH approach, which can effectively utilize and recycle CO 2 , offers competitive advantages in developing entirely ecofriendly processes and devices, as well as a viable avenue to improve biocompatible materials and electronics.

This paper proposes a math-physical correlative method that monitors deep defect response by electrical measurement and calculates the state density by designed mathematical processing. The extracted Gaussian distribution of deep defects was discussed according to the theoretical model for the density of states. The accuracy of this method was also verified through 1/f low frequency noise analysis. The origination of deep defects was investigated by transmission electron microscope, x-ray photoelectron spectroscopy, and photoluminescence analysis, and a molecular model was constructed. Therefore, multiple perspectives of deep defects have been studied by combining electrical measurements, mathematical data processing, and materials analysis, providing inspiration for future comprehensive study on deep defects of the GaN-based device.

epitaxial layers on silicon enables the use of existing silicon manufacturing infrastructure, eliminating the need for costly specific production facilities and leveraging large diameter silicon wafers at low cost. [10,11] Although silicon is a relatively cheap substrate compared with other substrate candidates, but has some distinct disadvantages since silicon and GaN are unmatched material systems. [12] The discrepancies in crystalline structure of GaN and silicon leads to higher lattice mismatches, behaving like dislocations and other types of defects. [13][14][15][16] The crystal defects affect the device performance and reliability to a large extent. A typical conundrum in GaN filed is related to the fact that the dislocations/lattice mismatch could exert inevitable negative effects on the device's basic performance, stability, and reliability. [17][18][19][20] Intensive researches indicated that charge trapping process caused by defects significantly affect the device performance. [21][22][23][24][25][26][27] As the most promising power device, gallium nitride (GaN)-based high electron mobility transistors (HEMTs) typically works under high voltage over a prolonged period. The long-term accumulation of heat during the operation appears to be another unfavorable factor that deteriorates the reliability. [28][29][30][31] The general degradation of electrical performance under negative bias condition at elevated temperatures is collectively known as negative bias temperature instability (NBTI) problem. [32] Although the NBTI problem was first noticed and mainly discussed in p-MOSFET devices, [33][34][35][36] it also perplexes depletion-mode or normally-ON GaN-HEMTs which is the most frequently used GaN device. [37][38][39][40][41][42][43][44] NBTI-related issues in depletion-mode GaN-HEMTs with different kinds of dielectric layer have been investigated in a series of researches. [41,[45][46][47][48][49][50] The NBTI-induced reliability issues in GaN-HEMTs have been acknowledged as a major concern that contributes to the operational instability. While intensive efforts have been made to optimize it from the perspective of manufacturing process or selected materials, [45,51,52] insufficient attention has been devoted to fundamental understanding of the intrinsic mechanisms. Some studies [41][42][43][44][45][46] attributed the degradation to the charge and discharge process of defects at the interface of GaN buffer layer and dielectric layer, while others [47][48][49][50] considered the degradation cause is not only the interface