High-performance Electronics Research Articles

Quantitative characterization of thin-film cracking behavior enabled by one-step asymmetrical bending

Quantitative characterization of crack behavior in thin-film materials is a fundamental issue in solid mechanics and is of necessity for the development of high-performance flexible electronics. However, such analysis largely relies on the complicated in-situ microscopy technique and the operational skills of experienced researchers, thus leading to difficulties in its widespread applications. To address this challenge, we report herein a facile and efficient characterization method based on the asymmetrical bending strategy to achieve the quantitative analysis of the crack features in thin-film materials without any need for specialized testing instruments. The key to this method is to bend two unparallel edges of the trapezoid-shaped thin film/substrate to form an asymmetrical configuration, in which the local bending radius changes linearly along the bending axis. As such, a large number of bending radii can be achieved on one single sample in one experiment, which significantly simplifies the process of quantitatively relating crack features to mechanical deformation. As a proof-of-concept demonstration, we employ this method for the one-step in-situ investigation of the crack behavior of the Cu film on a polymeric substrate.

Synthesized silver nanoparticles decorated reduced graphene oxide/silver ink for aerosol jet printed conformal temperature sensor with a wide sensing range and excellent stability

Three-dimensional (3D) conformal printing of temperature sensors with a wide sensing range and high stability requires the potential printable material with excellent functionality and printability. Herein, a high-performance silver nanoparticles (Ag NPs) decorated reduced graphene oxide (RGO)/Ag (ADR/Ag) ink with low viscosity was synthesized for aerosol jet printing (AJP). Ag ions are electrostatically adsorbed on the graphene oxide (GO) surface, and Ag NPs (∼10 nm) were attached onto the RGO surface by in-situ liquid-phase reduction. The ADR nanoflakes were mixed with commercial Ag NPs ink, high resolution patterns with ink stream widths down to 10 μm are printed, and ADR/Ag-0.8% ink shows excellent low-temperature sintering capability and flexibility, and the resistivity of the printed traces is 9.79 × 10−5 Ω m after 1 h sintering at a relatively low temperature (75 °C). The resistance negligibly increases by only 5% after 1000 bending cycles, which is about 7 times lower compared to the pure Ag traces. Furthermore, we achieve the 3D printing of a conformal temperature sensor with a sensitivity range of (1.162–1.519) × 10−3/°C in the broad sensing range of 0–200 °C. These findings shed light on the additive manufacturing of high-performance conformal electronics using the emerging AJP technology.

Strain localization in wearable integrated electronics using dot pattern

Sensors and actuators can now achieve high levels of stretchability and functionality owning to the recent development of stretchable electronics. One main factor in creating high-performance stretchable electronics that can be adequately transferred to curved surfaces, such as human skin, is the conformal design of the island-bridge model. In island-bridge models, interconnect conductors (bridges) are the most vulnerable. Thus, it is necessary to preserve the durability and functionality of interconnect conductors under high strains. In this study, by transferring dots to the main substrate, the interconnect conductors can be protected. This causes the strain to become localized in the region between the two neighboring islands. This region is known as safe region. In the safe region, the strains bypass the other side of the stretchable electronic from the upper and lower parts. This objective was achieved using the experimental tensile test and finite element analysis. These results displayed a 4% − 9% reduction in the average strain of safe region while applying 10% − 30% strain. The design parameters were optimized with energy release rate measurement. Additionally, the interconnect conductors’ path in the safe region was optimized improving this value to at least 50% below its applied strain. This design made the stretchable electronic significantly durable while maintaining its functionality.

Fabricating 1D stretchable fiber-shaped electronics based on inkjet printing technology for wearable applications

Advanced microfabrication on small and curved fiber surfaces remains a critical challenge and an urgent need to develop high-performance fiber-shaped electronics and advance the next generation of wearable electronics technology. In this study, we propose the preparation of 1D stretchable fiber-shaped electronics via inkjet printing technology for wearable applications. Utilizing self-built precision rotary inkjet printing equipment and a surface chemical modification process, we achieve high-precision and customizable microfabrication onto ultra-low diameter fiber surfaces (minimum printing line width of 133 µm and a printable fiber diameter as low as 500 µm with a large curvature of 4000 m−1). More importantly, this fabricating method is non-destructive and can prepare 1D stretchable conductors by printing conductive inks with stretchable structures and optimizing various synthetic fibers, which exhibit remarkable conductivity, mechanical stability, and strain-insensitive properties in practical applications. Furthermore, we demonstrate the performance of several 1D stretchable electronics applications, including a fiber-shaped electrothermal device, triboelectric strain sensor, and supercapacitor. Our work will greatly promote the development of 1D fiber-shaped electronics and smart textiles with wearability, high performance, functional diversification, and low cost.

Ultrathin Crystalline Silicon Nano and Micro Membranes with High Areal Density for Low-Cost Flexible Electronics.

Ultrathin crystalline silicon is widely used as an active material for high-performance, flexible, and stretchable electronics, from simple passive and active components to complex integrated circuits, due to its excellent electrical and mechanical properties. However, in contrast to conventional silicon wafer-based devices, ultrathin crystalline silicon-based electronics require an expensive and rather complicated fabrication process. Although silicon-on-insulator (SOI) wafers are commonly used to obtain a single layer of crystalline silicon, they are costly and difficult to process. Therefore, as an alternative to SOI wafers-based thin layers, here, a simple transfer method is proposed for printing ultrathin multiple crystalline silicon sheets with thicknesses between 300nm to 13µm and high areal density (>90%) from a single mother wafer. Theoretically, the silicon nano/micro membrane can be generated until the mother wafer is completely consumed. In addition, the electronic applications of silicon membranes are successfully demonstrated through the fabrication of a flexible solar cell and flexible NMOS transistor arrays.

A Semi-Crystalline Polymer Semiconductor with Thin Film Stretchability Exceeding 200.

Despite the emerging scientific interest in polymer-based stretchable electronics, the trade-off between the crystallinity and stretchability of intrinsically stretchable polymer semiconductors-charge-carrier mobility increases as crystallinity increases while stretchability decreases-hinders the development of high-performance stretchable electronics. Herein, a highly stretchable polymer semiconductor is reported that shows concurrently improved thin film crystallinity and stretchability upon thermal annealing. The polymer thin films annealed at temperatures higher than their crystallization temperatures exhibit substantially improved thin film stretchability (> 200%) and hole mobility (≥ 0.2cm2 V-1 s-1 ). The simultaneous enhancement of the crystallinity and stretchability is attributed to the thermally-assisted structural phase transition that allows the formation of edge-on crystallites and reinforces interchain noncovalent interactions. These results provide new insights into how the current crystallinity-stretchability limitation can be overcome. Furthermore, the results will facilitate the design of high-mobility stretchable polymer semiconductors for high-performance stretchable electronics.

Design and synthesis of C@MoSe2@NMWCNT heterostructure as anode material for Na+ batteries via Mo-based organic complexes

Theoretically, molybdenum selenide (MoSe2) has the characteristic of high storage capacity for sodium ions, but it shows poor rate performance and cycle stability in actual sodium storage experiments. Additionally, heteroatom doping is beneficial to the high electronic performance of carbon materials. For example, the addition of nitrogen (N) to carbon nanotubes (CNT) leads to additional electrons on the surface of CNT, thus enhancing CNT conductivity. Herein, employing N-doped multi-wall CNT (NMWCNT), we synthesized C@MoSe2@NMWCNT nanocomposites that are endowed with heterojunctions. The results of DFT calculation suggest that the electron transfer intensity between the interfaces of C@MoSe2@NSWCNT (SW stands for single-wall) is obviously higher than that of C@MoSe2@SWCNT, and NSWCNT plays a role in promoting the electron transfer. In addition, the combination of MoSe2 with SWCNT can effectively reduce the Na+ diffusion energy barrier between MoSe2 layers in the C@MoSe2@NSWCNT composite (lowered from 0.91 to 0.69 eV), hence promoting Na+ mobility, and thus improving the performance of the system for Na+ storage. Experimentally, the PEG-200-2-C@MoSe2@NMWCNT system exhibited capacity of 226 mA h g−1 after 1100 cycles and 168 mA h 01 after 3600 cycles at a current density of 2 A g−1. Under the synergistic effect of carbon coating and NMW`CNT network, the stability of the Na+ storage of MoSe2 is significantly improved. This work can shed light for the research of nitrogen doped carbon-based materials.

Two-Dimensional Layered Materials Meet Perovskite Oxides: A Combination for High-Performance Electronic Devices.

As the Si-based transistors scale down to atomic dimensions, the basic principle of current electronics, which heavily relies on the tunable charge degree of freedom, faces increasing challenges to meet the future requirements of speed, switching energy, heat dissipation, and packing density as well as functionalities. Heterogeneous integration, where dissimilar layers of materials and functionalities are unrestrictedly stacked at an atomic scale, is appealing for next-generation electronics, such as multifunctional, neuromorphic, spintronic, and ultralow-power devices, because it unlocks technologically useful interfaces of distinct functionalities. Recently, the combination of functional perovskite oxides and two-dimensional layered materials (2DLMs) led to unexpected functionalities and enhanced device performance. In this paper, we review the recent progress of the heterogeneous integration of perovskite oxides and 2DLMs from the perspectives of fabrication and interfacial properties, electronic applications, and challenges as well as outlooks. In particular, we focus on three types of attractive applications, namely field-effect transistors, memory, and neuromorphic electronics. The van der Waals integration approach is extendible to other oxides and 2DLMs, leading to almost unlimited combinations of oxides and 2DLMs and contributing to future high-performance electronic and spintronic devices.

A Performance Optimized CSTBT with Low Switching Loss.

A novel Performance Optimized Carrier Stored Trench Gate Bipolar Transistor (CSTBT) with Low Switching Loss has been proposed. By applying a positive DC voltage to the shield gate, the carrier storage effect is enhanced, the hole blocking capability is improved and the conduction loss is reduced. The DC biased shield gate naturally forms inverse conduction channel to speed up turn-on period. Excess holes are conducted away from the device through the hole path to reduce turn-off loss (Eoff). In addition, other parameters including ON-state voltage (Von), blocking characteristic and short circuit performance are also improved. Simulation results demonstrate that our device exhibits a 35.1% and 35.9% decrease in Eoff and turn-on loss (Eon), respectively, in comparison with the conventional shield CSTBT (Con-SGCSTBT). Additionally, our device achieves a short-circuit duration time that is 2.48 times longer. In high-frequency switching applications, device power loss can be reduced by 35%. It should be noted that the additional DC voltage bias is equivalent to the output voltage of the driving circuit, enabling an effective and feasible approach towards high-performance power electronics applications.

Assessing the Potential of Heat Pumps to Reduce the Radiator Size on Small Satellites

Future small satellites will demand high-performance on-board electronics, requiring sophisticated approaches to heat rejection beyond simply increasing the radiator surface area. An interesting alternative approach is to increase the surface temperature of the radiator, using a heat pump. In this study, calculations were carried out to compute the theoretical radiator size reduction potential enacted by having a heat pump as part of a satellite’s thermal management system. The practical likelihood of a ‘typical’ vapor compression cycle (VCC) heat pump satisfying theoretical requirements was considered. In agreement with theoretical calculations, employing a ‘typical’ VCC heat pump could either increase or decrease the required radiator surface area. The choice of heat pump and its design is therefore crucial. A heat pump with a large temperature lift is essential for satellite radiator cooling applications, with the coefficient of performance (COP) being less important. Even with a low COP, such as 2.4, a ‘typical’ heat pump providing a large temperature lift, close to 60 °C, could reduce the satellite’s radiator surface area by a factor close to 1.4. This is a significant potential reduction. The decision on whether to pursue this approach compared to alternatives, such as deployable radiators, should consider the relative complexity, cost, weight, size, reliability, etc., of the two options. The focus of this study is VCC heat pumps; however, the results provide performance targets for less mature heat pump technologies, e.g., caloric devices, which could ultimately be applied in space.

Enhancing the enrichment of conjugated polymer at surfaces of its elastomer blend film via increasing molecular weight to induce desired nanofibril network for highly stretchable polymer film

The vertical phase separation in conjugated polymer-elastomer blend systems plays a critical role in inducing desired film morphology of interconnected polymer nanofibrils for high-performance stretchable electronics. However, the precise control of vertical component distribution remains a great challenge due to the complex interactions among solutes, solvent and substrate in the blend system. Herein, we proposed a strategy to enhance the enrichment of polymer at film surfaces in the conjugated polymer-elastomer blend via increasing polymer molecular weight and systematically investigated the microstructural transition of blends under strain. For this purpose, a number of N2200 polymers with the number-average molecular weight (Mn) below (28, 57, 96 kDa) and above (143 kDa) the critical molecular weight (Mc) were used to blend with SEBS. With the increase of Mn, the phase separation between N2200 and SEBS along depth direction occurred at a greater extent due to the reduced polymer solubility and miscibility of the two components. Film-depth-dependent light absorption spectroscopy (FLAS) measurement shows that the content of N2200 concentrated at the film surfaces is dramatically increased from 66% to 85% as the Mn increases from 28 to 143 kDa, leading to the change of morphology from isolated aggregates to continuous and entangled nanofibril network within SEBS matrix. Under deformation, these nanofibrils formed in the 143 kDa blend film are able to maintain sufficient connections and the crystallites are seldom destroyed, thus guarantee efficient charge transport channels. The mobility of the 143 kDa blend film is 0.188 cm2 V−1 s−1, much higher than that of 28 kDa blend film (0.043 cm2 V−1 s−1) and does not decrease during stretching up to 150% strain.

Surface-engineered binder-free PEDOT shielded nickel magnesium selenide nanosheet arrays electrode for ultralong-life flexible quasi-solid-state hybrid supercapacitors

Together with the development of high-performance advanced electronics, flexible supercapacitors (SCs) with tailored nanostructures have great attraction. Electrochemically deposited nanosheet arrays of nickel magnesium selenide (NixMg3-xSe4, NMgS) with high capacitance provide high potentials as a positive electrode in flexible SCs. To further enhance their electrochemical properties and long-term cycling stability, a promising strategy of surface engineering with conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) is proposed. The present work proposes the construction of PEDOT shielded NMgS (P@NMgS-2) on a flexible carbon cloth substrate via a hierarchical electrodeposition technique. Benefitting from the synergistic effect, the P@NMgS-2 exhibits an excellent areal capacitance value of 1440 mF cm−2 at 4 mA cm−2. A novel shape-adaptable polymer gel electrolyte-assisted flexible quasi-solid-state hybrid SC (FQHSC) device constructed with P@NMgS-2 as a positive electrode and activated carbon as a negative electrode demonstrates the maximum power and energy density values of 14.13 mW cm−2 and 0.18 mWh cm−2, respectively, followed by outstanding cycling stability (∼100% capacitance retention over 50,000 cycles). Furthermore, the FQHSC device successfully powered electronic devices with no serious degradation upon bending and twisting for wearable electronic applications.

GaN/Gr (2D)/Si (3D) Combined High-Performance Hot Electron Transistors.

To overcome the problem of minority carrier storage time in bipolar transistors, a hot electron transistor (HET) has been proposed. This device has the advantage of high working speed and some complex logic functions can be completed by using one component. Here, we demonstrate a mixed-dimensional HET composed of GaN/AlN microwires, graphene (Gr), and Si. The electrons between GaN/AlN are injected into graphene by an F-N tunneling mechanism to achieve high speed hot electrons, then cross graphene by ballistic transport, and are collected in a nearly lossless manner through a low-barrier Si. Therefore, the device shows a record DC gain of 16.2, a collection efficiency close to the limit of 99.9% based on the graphene hot electron transistor (GHET), an emitter current density of about 68.7 A/cm2, and a high on/off current ratio reaching ∼107. Meanwhile, the current saturation range is wide, beyond those of most GHETs. It has potential applications as a power amplifier.

An Ortho-Bisalkyloxylated Benzene-Based Fully Non-fused Electron Acceptor for Efficient Organic Photovoltaic Cells.

To develop the low-cost nonfullerene acceptors (NFAs), two fully non-fused NFAs (TBT-2 and TBT-6) with ortho-bis((2-ethylhexyl)oxy)benzene unit and different side chains onto thiophene-bridges are synthesized through highly efficient synthetic procedures. Both acceptors show good planarity, low optical gaps (≈1.51eV), and deep highest occupied molecular orbital levels (≤-5.77eV). More importantly, the single-crystal structure of TBT-2 shows compact molecular arrangement due to the existence of intramolecular interactions between adjacent aromatic units and strong π-π stacking between intermolecular terminal groups. When the two acceptors are fabricated organic photovoltaic (OPV) cells by combining with a wide optical gap polymer donor, the TBT-6 with strong crystallization forms large domain sizes in bulk heterojunction (BHJ) blend. As a result, the TBT-6-based OPV cell shows a low power conversion efficiency (PCE) of 9.53%. In contrast, the TBT-2 with proper crystallization facilitates morphological optimization in the BHJ blend. Consequently, the TBT-2-based OPV cell gives an outstanding PCE of 13.25%, which is one of the best values among OPV cells with similar optical gaps. Overall, this work provides a practical molecular design strategy for developing high-performance and low-cost electron acceptors.

Wafer-scale high-κ dielectrics for two-dimensional circuits via van der Waals integration

The practical application of two-dimensional (2D) semiconductors for high-performance electronics requires the integration with large-scale and high-quality dielectrics—which however have been challenging to deposit to date, owing to their dangling-bonds-free surface. Here, we report a dry dielectric integration strategy that enables the transfer of wafer-scale and high-κ dielectrics on top of 2D semiconductors. By utilizing an ultra-thin buffer layer, sub-3 nm thin Al2O3 or HfO2 dielectrics could be pre-deposited and then mechanically dry-transferred on top of MoS2 monolayers. The transferred ultra-thin dielectric film could retain wafer-scale flatness and uniformity without any cracks, demonstrating a capacitance up to 2.8 μF/cm2, equivalent oxide thickness down to 1.2 nm, and leakage currents of ~10−7 A/cm2. The fabricated top-gate MoS2 transistors showed intrinsic properties without doping effects, exhibiting on-off ratios of ~107, subthreshold swing down to 68 mV/dec, and lowest interface states of 7.6×109 cm−2 eV−1. We also show that the scalable top-gate arrays can be used to construct functional logic gates. Our study provides a feasible route towards the vdW integration of high-κ dielectric films using an industry-compatible ALD process with well-controlled thickness, uniformity and scalability.

High-field 1/f noise in hBN-encapsulated graphene transistors

$1/f$ electronic noise is a conductance fluctuation, expressed in terms of a mobility ``$\ensuremath{\alpha}$-noise'' by Hooge and Kleinpenning. Understanding this noise in graphene is key for high-performance electronics. Early investigations pointed out a deviation from the standard Hooge formula, with the free-carrier density substituted by a constant density ${n}_{\mathrm{\ensuremath{\Delta}}}\ensuremath{\sim}{10}^{12}\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$. Here we investigate hBN-encapsulated graphene transistors where high mobility gives access to the velocity-saturation regime. We show that $\ensuremath{\alpha}$-noise is still accounted for by the Hooge formula on substituting conductance by differential conductance $G$, resulting in a bell-shaped dependence of flicker noise with bias voltage. The same analysis holds in the Zener regime at even larger bias, with two main differences. The first one is a strong enhancement of the Hooge parameter reflecting the hundred-times larger coupling of interband excitations to the hyperbolic phonon-polariton (HPhP) modes of the midinfrared Reststrahlen (RS) bands of hBN, which is supported by microwave noise thermometry measurements. The second is an exponential suppression of this coupling at large fields, which we attribute to decoherence effects. The phenomenology of $1/f$ noise in graphene supports a quantum-coherent bremsstrahlung interpretation of $\ensuremath{\alpha}$-noise.

Stretchable conductive hydrogel with super resistance-strain stability and ultrahigh durability enabled by specificity crosslinking strategy for high-performance flexible electronics

Stretchable ionic conductive hydrogels (SICHs) are regarded as one of the indispensable components for flexible electronics desirable to provide stable signal transmission and functional reproducibility. However, the state-of-the-art SICHs demonstrate a narrow resistance-stability range and poor cyclical fatigue reliability due to ion migration limitations and the absence of the molecular design regime. Herein, we present a novel synthetic strategy that utilizes the dynamic Zn-carboxyl physical bonding, adjacent to B-hydroxyl chemical bonding, to realize the “specificity” cross-linking in pectin polymeric networks. This approach significantly extends the resistance-stability range of SICHs, while also providing remarkable longevity. Via “specificity” crosslinking design, the Zn-carboxyl physical bonding, bearing thermodynamically stable and dynamic exchange character, can break the resistance-strain dependence of ionic conductive hydrogel, offering an unprecedented resistance-stability under largely applied strain (300%). Moreover, the B-hydroxyl chemical bonding effectively overcomes the conductivity and mechanical strength trade-off dilemma due to its strong but dynamic feature, realizing the high durability of SICHs. In addition, the extraordinary tolerate harsh environment capacity was achieved by introducing glycerin to form rich hydrogen bonds in the SICHs network, which is crucial for the avoidance of congelation at subzero temperatures and dehydration resulting from the circuit heat. As a stretchable conductive component of deformable electronic devices, the SICH demonstrates extraordinary long life and stable operation. These observations reveal fresh stretchable conductive materials.

Flexible, stripe-patterned organic solar cells and modules based on multilayer-printed Ag fibers for smart textile applications

Rapid advancement in the fabrication technologies of stripe/fiber-shaped optoelectronic devices has driven the performance of smart textile electronics to a new height. In the development of high-performance smart textile electronics, indium tin oxide (ITO)-free flexible transparent conductive electrodes (TCEs) are particularly desirable because they offer superior flexibility and lower manufacturing cost than the brittle ITO-based counterparts. Herein, we innovatively combine spin-coating and three-dimensional direct-ink writing (three-dimensional-DIW) techniques to develop large-area (5 × 5 cm2) PEDOT:PSS/Ag-fibers hybrid TCEs (denoted as DIW-TCEs) for application in flexible organic solar cells (OSCs). Through a multilayer printing strategy, high aspect-ratio Ag-fibers are successfully deposited on top of the planar PEDOT:PSS film. The resulting DIW-TCEs, when fully embedded in a colorless polyimide substrate, exhibit excellent electrical conductivity (sheet resistance ∼ 4 Ω/□), superior optical transmittance, and mechanical flexibility. One-dimensional stripe-patterned OSCs (stripe-OSCs) based on DIW-TCEs achieved power conversion efficiency of 9.3% and 8.2% at an active area of 0.11 cm2 and 0.31 cm2, respectively. For real-life application, a flexible power module was constructed using eight stripe-OSCs. When attached on textile, the module successfully lit up a commercial light-emitting diode upon photocharging. The unique DIW-TCE fabricated herein can be the ITO-free alternative for the production of smart textile electronics.

Fabrication of Advanced Cellulosic TriboelectricMaterials via Dielectric Modulation.

The rapid rise of triboelectric nanogenerators (TENGs), which are emerging energy conversion devices in advanced electronics and wearable sensing systems, has elevated the interest in high-performance and multifunctional triboelectric materials. Among them, cellulosic materials, affording high efficiency, biodegradability, and customizability, are becoming a new front-runner. The inherently low dielectric constant limits the increase in the surface charge density. However, owing to its unique structure and excellent processability, cellulose shows great potential for dielectric modulation, providing a strong impetus for its advanced applications in the era of Internet of Things and artificial intelligence. This review aims to provide comprehensive insights into the fabrication of dielectric-enhanced cellulosic triboelectric materials via dielectric modulation. The exceptional advantages and research progress in cellulosic materials are highlighted. The effects of the dielectric constant, polarization, and percolation threshold on the charge density are systematically investigated, providing a theoretical basis for cellulose dielectric modulation. Typical dielectric characterization methods are introduced, and their technical characteristics are analyzed. Furthermore, the performance enhancements of cellulosic triboelectric materials endowed by dielectric modulation, including more efficient energy harvesting, high-performance wearable electronics, and impedance matching via material strategies, are introduced. Finally, the challenges and future opportunities for cellulose dielectric modulation are summarized.

Carbon nanotube network film-based field-effect transistor interface state optimization by ambient air annealing

Carbon nanotube field-effect transistors (CNTFETs) have been considered a strong candidate for post-Si era electronics due to the virtues of higher speed, lower power consumption, and multiple functionalities. The interface analysis based on the top gate structure has made little progress and lacks a reliable charge trap characterization model suitable for carbon tube devices. Quantitative extraction and analysis of the interface state are crucial for the integration of top-gate devices. Herein, a 5 nm thick Y2O3 thin film was selected as the gate dielectric layer in the top-gate CNTFETs device, and a post-annealing process in air ambience was utilized to optimize the Y2O3-CNT interface. A series of device performance evaluation results indicated that the post-annealing process in air ambience can effectively improve the on-state current and reduce the threshold voltage and subthreshold swing of the device, which are derived from diffusion of oxygen atom in the Y2O3 layer and optimization of the interface of Y2O3-CNT. Specifically, the maximum mobility, subthreshold swing, and threshold voltage are calculated to be 29 cm2/V s, 103 mV/dec, and −0.1 V, respectively, and the interface state density is reduced from 2.68 × 1012 to 1.51 × 1012 cm−2 in the gate insulator. These results not only are important to understand the dielectric impact on CNTFET devices but also are useful for future materials’ development and device optimization for high-performance CNT-based electronics.