ACS Applied Electronic Materials最新文献

Wide-bandgap (WBG) perovskite solar cells (PSCs) are pivotal for developing high-efficiency tandem solar cells; however, their performance is substantially limited by interfacial defects and nonradiative recombination. Herein, we introduce 1-butyl-3-methylimidazolium tosylate (BDMIMTS), an imidazolium-based ionic liquid, as a multifunctional additive incorporated via precursor doping. This approach simultaneously modulates perovskite crystallization kinetics, suppresses defect states, and optimizes interfacial energy alignment. We elucidate a multisite synergistic passivation mechanism: sulfonate anions form coordination bonds with undercoordinated Pb²⁺ species, while imidazolium cations constrain the movement of negatively charged halides via hydrogen bonding, thereby enhancing the passivation effect and effectively mitigating the influence of deep-level traps. The optimized devices achieve a power conversion efficiency (PCE) of 22.62%, an open-circuit voltage (V_OC) of 1.24 V, and an ultrahigh fill factor (FF) of 87.50%. Furthermore, encapsulated devices retain over 90% of their initial PCE after 1100 h in a nitrogen atmosphere. This work provides a strategic material design paradigm for enhancing the performance and stability of perovskite-silicon tandem solar cells, highlighting a promising pathway toward advanced photovoltaics.

Carbon nanotubes (CNTs) are promising candidates for next-generation back-end-of-line (BEOL) compatible devices due to their excellent scalability, energy efficiency, compatibility with low-temperature processes, and high-speed charge transport. However, top-gate carbon nanotube field-effect transistors (CNFETs) often suffer from high contact resistance R_C, which significantly reduces the on-state current and hinders the realization of high-performance devices. This is primarily attributed to gate-field screening at the contact–channel interface, which increases R_C compared to their back-gate counterparts. In this work, we address this limitation through a combination of numerical modeling and experimental validation using self-aligned contact doping enabled by MoO_x nanoparticles. A self-consistent one-dimensional Poisson solver coupled with the Landauer–Büttiker formalism reveals that contact doping improves the Schottky barrier and enhances carrier tunneling. Experimentally, top-gate CNFETs with 0.8 nm MoO_x-doped Pd contacts exhibit a 58% reduction in R_C, a significant increase in output current, and a reduction in effective Schottky barrier height from 72 to 20 meV, while maintaining long-term stability for over 71 days. Furthermore, Monte Carlo simulations incorporating realistic CNT diameter distributions predict a reduction of up to 52% in dense CNT arrays with a diameter of 1.0 nm. This study provides both fundamental insight and experimental demonstration of self-aligned MoO_x contact doping as a scalable strategy to mitigate contact resistance in top-gate CNFETs.

Reliance on external power sources remains a significant constraint for the practical deployment of flexible sensors. Herein, we develop a multifunctional hydrogel-based sensor that operates in two distinct modes: a self-powered mode for humidity sensing and a resistance mode for strain detection. The sensor is built around a conductive poly(vinyl alcohol)-graphene oxide/lithium bromide (PVA-GO/LiBr) hydrogel, fabricated via a straightforward one-step process. This core material exhibits a high ionic conductivity of 0.33 S·cm^–1. In its self-powered humidity-sensing mode, the device leverages a metal–air redox reaction, where moisture-triggered ion mobility generates a current output with a sensitivity of 0.299 nA/s per % RH in the 70% to 90% RH range. Simultaneously, the intrinsic resistance of the very same hydrogel structure serves as a highly responsive strain gauge, capable of achieving a 6-fold increase in resistance at 400% tensile strain. Demonstrating robust performance even at −15 °C, the sensor is integrated into a respiratory monitoring platform. It successfully enables the real-time detection of abnormal breathing patterns, such as sleep apnea hypopnea syndrome (SAHS), showcasing its potential as a scalable and power-efficient solution for advanced wearable health diagnostics and telemedicine.

Functional conductive coatings on polymer substrates are essential for the next generation of plastic-based electronics, facilitating reliable electrical interconnections, embedded circuitry, energy-harvesting modules, and the seamless integration of wearable and sensing systems, while preserving the inherent advantages of polymeric materials, including lightweight, manufacturing flexibility, and cost-effective production. Material extrusion (MEX)-based 3D-printing offers geometric flexibility for such components; however, effective area-selective metallization in MEX has primarily relied on composite filaments with high wt % conductive fillers, followed by electroless plating (ELP). In these systems, conductive particles often remain embedded beneath the printed polymer layers, necessitating additional postprocessing to expose them for ELP, yet even then, the electrical performance remains limited. This study presents an advanced dip-coating strategy for producing Cu-coated ABS filaments, enabling the direct formation of surface-exposed nucleation sites during MEX printing. The acetone-mediated Cu deposition process yielded filaments with an electrical resistivity of 2.075 × 10^–3 Ω·cm, while preserving extrusion performance. Printed circuitry pathways exhibited continuous, surface-exposed Cu regions that served as preferential sites for Pd accumulation during brief Pd/Sn activation, thereby intrinsically enabling area-selective ELP without any additional selective treatment of the pathways. Subsequent Cu deposition achieved electrical conductivity up to 85.77% of bulk copper while maintaining strong metal–polymer adhesion (ASTM D3359 ratings of 4B–5B). By integrating AM with targeted surface functionalization, this approach offers a scalable and sustainable route to fabricate highly conductive, adherent coatings on polymeric structures, advancing functional coating technologies for plastronics and related applications.

Logical operations and an encrypted scheme are promising for the artificial intelligence field. However, it is still challenging to realize multi-input logical integration and multistate secure encryption. Herein, a WSe₂-based triple-gated field-effect transistor (TG-FET) is designed, in which the current states are strongly dependent on different gate synergetic regulations. For a single device, the artificial neural algorithm is used to verify the logic operation and anti-interference, and the noise margin of the three-input NOR gate (NOR-3) is up to 50%. The quaternary current states correspond to a double-binary bit array. By taking the conversion between binary and quaternary information as the encryption rule, multistate encrypted image and data can be obtained, which significantly enhances the difficulty of information decryption. Moreover, through cascading two, three, and four NOR-3 gates, gate voltage modulation is only required to implement a three-input XNOR gate, majority voter, and 4:1 multiplexer, respectively. This work provides a route to enhance the parallel freedom degree of data processing and protect information privacy.

We present a targeted investigation of GA⁺/Co²⁺ dual-site engineering in tin halide perovskites, GA(Sn_1–xCo_x)I_2–2xCl_1+2x, establishing its quantitative impact on structural stabilization and electronic optimization in lead-free photovoltaics. GA⁺ incorporation strengthens the perovskite framework through A-site steric stabilization and effective suppression of Sn oxidation pathways, while Co²⁺ alloying modifies the B-site potential landscape to yield tunable direct bandgaps of 1.26–1.40 eV, enhanced dielectric screening (ε_r ≈ 10), and a high absorption coefficient (α > 10⁴ cm^–1). This dual-site strategy reduces deep-level trap formation and mitigates ionic migration, outperforming conventional Sn-based systems in both thermodynamic robustness and carrier recombination kinetics. Device simulations of a TiO₂/perovskite/Cu₂O stack predict a theoretical efficiency of 19.61% with improved V_oc, reduced interfacial recombination resistance, and a built-in potential of ∼1.19 V, consistent with strengthened internal electrostatics induced by GA⁺/Co²⁺ synergy. These results demonstrate that coordinated A- and B-site modification provides a mechanistically coherent route to stabilize Sn-based perovskites while achieving competitive, lead-free photovoltaic performance.

Flexible pressure sensors play an essential role in wearable electronics, human–machine interfaces, and physiological monitoring systems. Achieving both high sensitivity and a wide dynamic range remains a major challenge. Here we report a piezoresistive flexible pressure sensor based on graphitic carbon nitride (g-C₃N₄) that addresses this longstanding trade-off through multiscale dimensional engineering of silver (Ag)-based sensing materials. Three Ag-based materials with distinct dimensional characteristics, Ag single atoms, Ag single atom cluster hybrids, and Ag nanoparticles, were synthesized and their piezoresistive behaviors were evaluated across different pressure regimes. The sensor exhibits an ultrafast response and recovery time of 0.5/0.4 s and high reproducibility. Sensing performance shows pronounced size-dependent behavior with nanoparticles providing a robust response at high pressures (>4.5 kPa), single atom cluster hybrids showing optimal sensitivity in the intermediate range (3–4.5 kPa), and single atom sites exhibiting comparable behavior to single atom cluster hybrids at low pressures (<3 kPa). Integration into a robotic hand demonstrates the sensor’s practical applicability, enabling precise tactile control under low pressure (0.85 kPa). This work establishes a generalizable strategy for decoupling sensitivity and dynamic range by engineering Ag from atomic to nanoscopic scales, offering broad applicability in wearable electronic and robotic tactile systems.

Rare-earth element engineering has emerged as a pivotal strategy for boosting the piezoelectric performance of lead-free piezoelectrics. Herein, we introduce Nd³⁺ into highly promising lead-free perovskite (K, Na)NbO₃ (KNN) single crystals for the first time. High-quality Nd-doped KNN single crystals are grown by the Czochralski method. The incorporation of Nd elements results in a significant increase in the piezoelectric coefficient d₃₃ to 261 pC/N, a 1.57 times larger value compared to undoped KNN. Mechanistic analysis indicates that the highly enhanced piezoelectricity with the Nd doping strategy is caused by modulating the ferroelectric domain structure and reducing the oxygen vacancy concentration. This work provides a doping strategy via rare-earth-element doping to improve the KNN single crystals.

Mo(S_XSe_1–X)₂ alloys, which belong to the transition metal dichalcogenides (TMDs), have attracted considerable interest due to their tunable band gap and characteristic electrical and optical properties. As a result, they can find wide applications in optoelectronics. In this paper, the photodetectors based on monolayer Mo(S_XSe_1–X)₂ alloys were fabricated and studied over a wide range of temperatures and illumination. They exhibit unprecedented performance in the wavelength range from 460 to 630 nm─high responsivity (R = 9.08 × 10⁶ A W^1–) and specific detectivity (D* = 9.38 × 10¹³ Jones). Their properties change nonlinearly with increasing temperature. The MoS₂ and MoSe₂-based photodetectors show the best properties at T = 300 K, while Mo(S_XSe_1–X)₂-based photodetectors perform optimally at T = 250 K. In addition, we have proposed a design of buried electrodes intended to provide Ohmic contacts, over a wide range of ambient temperatures, with results indicating that this approach is highly promising, which has been confirmed in most of the investigated samples.

Flexible and highly sensitive strain sensors are necessary for the evolution of wearable electronics, soft robotics, and human–machine interfaces. In this study, we present an in situ synthesized PAni-rGO/Ecoflex-based strain sensor that demonstrates remarkable sensitivity, stretchability, and durability. The functionalized rGO provides uniform dispersion and improved interfacial adhesion inside the Ecoflex matrix, resulting in a stable 3D conductive network. The sensor exhibits an excellent gauge factor of ∼239.1, a wide sensing range (>120%), and outstanding long-term cyclic stability. The sensing mechanism integrates tunneling conduction, microcrack evolution, and hopping transport, where PAni employs its flexible conjugated chains to bridge microcracks and maintain partial connectivity. Thermogravimetric analysis showed great stability up to 100 °C, and resistance is unaffected by moisture absorption of more than 4%, ensuring environmental resilience. These characteristics make the sensor an attractive choice for next-generation wearable electronics and multifunctional intelligent sensing systems.