Synthesis of an immobilizable p-dopant and covalent binding onto a polymeric semiconductor

Electron-irradiation effects on Raman and infrared spectra of Te-doped n- and p-type silicon

n-type polymer semiconductors for organic thermoelectric materials

One-step Cu-Fe bimetal-assisted chemical etching for texturing silicon surfaces with ball-crown-shaped upright pyramids

Promoting hole mobility in carbon-based perovskite solar cells by p-type doping of P3HT to lower its hole reorganization energy

Semiconducting covalent organic frameworks (COFs) that combine structural order with porous characteristics are promising candidates for chemiresistive sensors. Understanding carrier transport behavior and improving their electrical properties remain critical challenges due to the low intrinsic conductivity of semiconducting COFs and the difficulty of electronic device fabrication. Herein, we propose a strategy that introduces acidic electron acceptors into a semiconductive COF, Py-1P, to modulate its electrical properties. Comprehensive characterizations confirmed charge-transfer interactions between electron acceptors and imine bonds, achieving a chemical doping effect. The modified COF-based chemiresistors exhibited a significantly enhanced sensing response for detecting sub-ppm NO2 gas, among the best reported chemiresistive sensors. The measurement of COF-based field-effect transistors (FETs) revealed a one-order-of-magnitude enhancement in mobility upon the p-type doping, indicating the corresponding relationship between carrier density and mobility in polycrystalline COFs. These findings provide a comprehensive understanding of doping effects and carrier transport in the semiconductive COF, establishing a foundation for optimizing COF-based electronic devices.

The metal-semiconductor contact interface is crucial for the performance of devices made from two-dimensional (2D) semiconductors, as it significantly influences the efficiency of charge carrier injection into the semiconductor channel. However, creating high-performance contacts for emerging 2D semiconductors, especially p-type semiconductors, presents several challenges. The performance of p-type devices is often limited by Fermi-level pinning and defect-mediated scattering at the interfaces, which create parasitic barriers that increase contact resistance. In this study, we focused on the low effective mass p-type semiconductor In2Ge2Te6 to systematically explore the combined effects of interface contact and doping engineering on optimizing device performance. Introducing optimized electrode and region-selective oxygen doping reduced the Schottky barrier height from 63 to 36meV and decreased the contact resistance from 1.3 to 0.6kΩµm, through matching work function and creating an impurity band that optimizes band alignment. Furthermore, we constructed an In2Ge2Te6/MoS2 complementary metal oxide semiconductor (CMOS) device, achieving an impressive voltage gain of 140 at VDD = 5V and a low peak static power consumption of 2.9 nW at VDD = 1V. This research presents a straightforward strategy for reducing contact barriers and enhancing performance in 2D p-type field-effect transistors (FETs) and CMOS devices.

Organic semiconductors (OSCs) are leading materials for next-generation optoelectronic devices. Effective charge transport in devices often requires electronic doping of OSCs. Conventional methods using molecular dopants or metal salts often suffer from poor efficiency, undesirable side products, and require additives and prolonged incubation. Under device operational conditions, these undesirable side products and additives lead to degradation in device performance. Here, an in situ regenerative adduct-assisted (IRAA) doping is presented, which is rapid, metal-ion-free, and requires no additives for dopant stabilization, enabling clean and efficient doping of various OSCs. Spectroscopic analyses reveal a self-regenerating adduct as the active doping species. The simplicity of the doping method and the range of materials available open new avenues for the development of diverse electronic-doping strategies, providing a scalable and universal approach to doping OSC-based hole-transporting layers for various types of optoelectronic devices, including halide perovskite solar cells.

Herein, porous boron nitride nanosheets (BNNS) exhibiting n-type semiconductor characteristics were synthesized via high-temperature pyrolysis. Subsequently, a series of Bi2O3/BNNS composites with superior photocatalytic activity were constructed using a solvothermal method. Experimental results demonstrate that the optimized composite photocatalyst exhibits significantly enhanced adsorption capacity and photocatalytic activity compared to pristine BNNS and Bi2O3. The optimal Bi2O3/BNNS composite achieved degradation efficiencies of 94.65%, 94.23%, and 93.97% for tetracycline (TC), oxytetracycline (OTC), and doxycycline (DC) (each at 50 mg L−1), respectively, under simulated solar irradiation. This study highlights that the exceptional adsorption capability of BNNS enables the Bi2O3/BNNS composite to fulfill the requirements for synergistic adsorption–photocatalysis. Furthermore, BNNS serves as an effective growth substrate, significantly regulating the growth of Bi2O3 nanowires and suppressing their agglomeration, thereby endowing the composite with a large specific surface area and pore volume. The formation of a p–n heterojunction also effectively suppresses the recombination of photogenerated charge carriers within the catalyst. Finally, this work elucidates the detailed process and underlying mechanism of photocatalytic tetracycline degradation driven by simulated sunlight. In summary, this study innovatively employs the Bi2O3/BNNS composite as a novel photocatalyst for tetracycline degradation and provides theoretical guidance for the design of advanced photocatalysts.

Copper doping represents the most established technological process in the current manufacturing of CdTe solar cells and modules. However, its self-compensation effect and rapid diffusion at junction locations impose limitations on both the device efficiency and long-term stability. In this study, a Cu2Sb thin film with controllable composition and thickness was synthesized on the CdTe surface via a substitution reaction, serving as the p-type doping source for the device. Comparative investigations were conducted to evaluate the effects of pure Cu, pure Sb, and Cu-Sb alloyed dopants on the photoelectronic performance of CdTe-based thin-film solar cells. Although pure Sb dopants exhibit inferior performance and cannot replace Cu as the primary dopant, they serve effectively as auxiliary dopants. Incorporating Sb into the Cu doping process increases the concentration threshold for device doping, thereby enhancing the device's overall doping concentration. The optimized device achieved a power conversion efficiency (PCE) exceeding 18%. Furthermore, appropriate Sb incorporation significantly improved device stability, maintaining 90% of the initial PCE after 50 days of normal operation. These results demonstrate that codoping with Cu and Sb via Cu2Sb provides a promising route for fabricating high-efficiency and highly stable CdTe thin-film solar cells and modules.

Short-wave infrared (SWIR, 1-3 µm) light has become indispensable for applications including remote sensing, mineral identification, night vision, vital sign monitoring, and disaster response due to its exceptional ability to penetrate scattering media under harsh conditions. Serving as a disruptive alternative to conventional inorganic counterparts, short-wave infrared organic photodetectors (SWIR-OPDs) leverage inherent advantages such as light weight, mechanical flexibility, and large-area solution processability. Current material platforms for SWIR-OPDs primarily focus on narrow bandgap polymers and small molecules. Among these, n-type small-molecules are particularly promising for sensitive SWIR-OPDs, owing to their well-defined molecular structures, high crystallinity, tunable light spectral response and energy levels, and excellent electron transport properties. This review summarizes recent advances in SWIR-OPDs based on n-type small molecular semiconductors. Key topics cover the fundamentals of devices, design strategies for narrow bandgap molecules, representative n-type small molecules, device engineering and potential applications of SWIR-OPDs. Finally, current limitations are discussed alongside an outlook for future development.

As the conventional binary CMOS technology approaches its fundamental limits in device scaling and energy efficiency, multivalued logic (MVL) has emerged as a promising strategy to enhance information density and computational capability. Two-dimensional tellurium (Te), owing to its outstanding hole transport properties, provides an attractive material platform for advanced logic devices. In this work, surface selenium-doped tellurium thin films (TexSe1-x) are employed as a key functional layer, exhibiting gate-tunable, p-type-dominated ambipolar transport behavior. By integrating TexSe1-x with n-type two-dimensional semiconductors, heterojunction devices with pronounced antiambipolar transport characteristics are constructed, establishing a solid foundation for novel logic functionalities. Based on these heterostructures, two representative logic device demonstrations are realized: (i) a binary inverter based on a TexSe1-x/MoS2 heterojunction, exhibiting a characteristic Λ-shaped voltage transfer curve; and (ii) a stable ternary inverter implemented in a TexSe1-x/MoSe2 device, showing a distinct W-shaped transfer characteristic with a logic-state switching ratio approaching 104. These results highlight the significant potential of tellurium-based heterostructures for scalable binary and multivalued logic devices, offering a viable platform for next-generation MVL circuits.

Non-benzenoid polycyclic aromatic hydrocarbons (PAHs) containing antiaromatic indacene or pentalene and aromatic azulene subunits emerged as compelling materials, distinguished by their unique electronic configurations, exceptional optoelectronic characteristics, and potential applications in organic electronics. However, their controllable synthesis remains challenging due to inherent instability and stringent electronic requirements. Herein, we present a modular synthetic strategy that enables the construction of stable non-benzenoid PAHs (1, 2, and 3) featuring indacene, pentalene, and azulene motifs through a carefully designed sequence of 5-exo-dig cyclization (with controllable E/Z-selectivity), nucleophilic addition, Friedel-Crafts cyclization and oxidative dehydrogenation. Comprehensive structural and electronic analyses revealed that 1 and 2 exhibit global antiaromaticity and 2 displays a more pronounced open-shell diradical character than 1, while 3 maintains a global aromaticity and a closed-shell structure. Notably, compound 2 demonstrated promising p-type semiconductor behavior with a hole mobility of up to 0.083 cm2 V-1 s-1. Additionally, all three compounds demonstrated remarkable stability under ambient conditions, underscoring their potential for practical applications in organic electronics.

Spin-polarized DFT-based computations have been performed using mBJ + U approximations to explore the structural, optoelectronic, magnetic, and thermoelectric characteristics of Pr2EuMO6 (M = Co, Fe) materials in the cubic (Fm3̄m) space group. The study has made the materials promising in spintronic applications due to their half-metallic nature. Magnetic analysis shows that the materials are ferromagnetic. The overall magnetic moments of Pr2EuCoO6 and Pr2EuFeO6 are 11 (µB) and 14 (µB), respectively. Optical analyses of the two materials are conducted in the 0 to 14 eV energy range. The optical parameter study indicates that the materials are excellent in terms of photovoltaic and high-energy absorbent applications. The Seebeck coefficient shows that Pr2EuCoO6 and Pr2EuFeO6 are n- and p-type semiconductors, respectively. The elevated values of ZT at room temperature suggest that both materials have good thermoelectric efficiency, and the rising values of PF with increasing temperature suggest that the two materials can be used in high-temperature thermoelectric applications.

Good thermoelectric (TE) materials with high energy conversion efficiency are required to improve energy utilization and help meet increasing energy demands. By combining first-principles calculations with the Boltzmann transport theory, this study systematically investigates the electronic structure, mechanical properties, and TE performance of the half-Heusler compounds BiLiSr and BiKSr for the first time. Phonon spectrum calculations indicate that BiXSr (X = Li and K) exhibits dynamic stability. The calculated elastic constants demonstrate that BiXSr (X = Li and K) is mechanically stable and ductile. Electronic structure analysis reveals that BiLiSr is a direct-bandgap semiconductor, whereas BiKSr is an indirect-bandgap semiconductor. The TE performance results for BiXSr (X = Li and K) show that the Seebeck coefficient is superior under p-type doping, whereas the power factor is higher under n-type doping. Under n-type doping conditions, the maximum power factor values for BiLiSr and BiKSr are 852.14 and 572.85 µW m-1 K-2, respectively. At 300 K, the lattice thermal conductivity of BiKSr is consistent with previous theoretical studies. At 900 K, the calculated electronic TE figure of merit (ZT e) for both BiLiSr and BiKSr is 0.99. Considering the dynamic stability, mechanical stability, and TE performance of BiXSr (X = Li and K), this series of compounds demonstrate potential as promising TE materials over a wide temperature range.

Distinguishing surface recombination from subsurface transport is vital for optoelectronics but remains challenging in scanning ultrafast electron microscopy (SUEM) because of signal convolution. Here, we demonstrate that the detector bias (Vf) enables effective depth-selective probing to spatially disentangle these competing dynamics within the near-surface region. Experiments on p-type silicon reveal a striking voltage-tunable contrast inversion, marking a transition from surface-dominated to subsurface-dominated regimes. We attribute this to a mechanistic competition between surface potential restoration governing collection and subsurface band flattening modulating emission. Multiphysics simulations confirm this framework by linking depth-dependent charge distributions to contrast evolution. We thus achieve independent visualization of spatially entangled processes, specifically isolating surface trapping from subsurface diffusion and providing a physical basis for resolving vertical carrier stratification.

Although the wafer-scale growth of n-type MoS2 and its NMOS devices already show great potential for application in future electronics with ultra-short channels, the development of a p-type two-dimensional semiconductor is still in an early stage. The CMOS-compatible fabrication and stable p-type transistor development are significant challenges that hinder the development of CMOS-based integrated circuits with ultra-low power. In this study, we realized the 2-inch wafer-scale growth of a monolayer WSe2 film and propose a strategy to achieve uniform doping by depositing 0.5 nm Au on the surface of WSe2via electron beam evaporation, followed by annealing. The results show that after annealing at 400 °C, the deposited thin Au layer aggregated to form Au nanoparticles, which were uniformly distributed on the surface of WSe2 films with a good interface, as proven by atomic-resolution cross-section analysis. Moreover, the investigation of the top-gate transistor arrays verified that the WSe2-Au sample annealed at 400 °C exhibited excellent doping stability and uniformity: the mobility increased by 46 times, the ON/OFF ratio improved by two orders of magnitude, and the subthreshold swing significantly reduced from 2.35 V dec-1 to 0.77 V dec-1. This uniform doping method shows great potential for the development of wafer-scale 2D materials in the field of integrated circuits.

A new synthetic strategy and associated mechanism have been developed, in which two carrier conduction channels of n- and p-type semiconductors on the surface of one material are automatically and advantageously selected during surface reactivity. The key step is to uniformly channel non-equilibrium metal oxides of CuOx and SnOx throughout the sample by applying a flame chemical vapour deposition technique for 5 s. Unlike the original SnO2 semiconductor and Cu metal, the resulting material possessed intermediate physicochemical properties. It has been demonstrated that an oxidising gas, NO2, and reducing gas, H2S, can be alternately adsorbed, which was facilitated by the automatic selection of p- or n-type channels. This solid-solution sensing method utilizing non-equilibrium compositions can be employed in other applications involving semiconducting metal oxide gas sensing, even at low temperatures.

The development of efficient p-type semiconductors is critical for advancing dye-sensitized solar cell (DSSC) technologies, particularly for improving the photocathode performance. Among potential candidates, delafossite-type oxides such as CuGaO2 have shown promising properties, including wide band gaps, high hole mobility, and favorable dye adsorption characteristics. However, the synthesis of phase-pure, nanoscale CuGaO2 remains a major challenge, especially through low-temperature routes compatible with device fabrication requirements. This work presents a microwave-assisted hydro-solvothermal method for the controlled synthesis of CuGaO2 nanoparticles. The influence of three critical parameters (coprecipitation pH, reducing agent quantity, and reaction time) on the phase purity and particle size was systematically investigated. The microwave-assisted approach enables rapid and uniform heating, promoting controlled nucleation and growth, while reducing the overall reaction time. Structural and morphological characterization confirmed the formation of nanoplate CuGaO2 with high phase purity under optimized conditions, eliminating the need for harsh post-synthesis treatments. This method provides a scalable and efficient route for producing high-quality CuGaO2 particles, offering a promising platform for integration in next-generation photovoltaic devices, as demonstrated by preliminary p-DSSCs investigations using P1 dye loading.

We report a high-performance thermoelectric pavonite compound, Ag0.5CdBi4.5Se8, featuring a unique quasi-superlattice structure assembled from five distinct polyhedral units ([AgSe6], [CdSe6], [(Bi1)Se5], [(Bi2)Se6], and [(Bi3)Se6]). Naturally arranged Bi-Se polyhedra with different distortions and crystallographic environments enable multidirectional orbital overlap, forming a quadruple-valley conduction band with a small energy separation of 0.07 eV. This electronic structure simultaneously enhances carrier transport and maintains a high Seebeck coefficient. Moreover, the inherently hybrid bonding network, which consists of alternating strong and weak bonds alongside coexisting ionic and covalent characters, combined with pronounced acoustic-optical phonon coupling originating from the [AgSe6]/[CdSe6] octahedra, results in an extremely low lattice thermal conductivity of 0.24 W m-1 K-1 at 823 K. While intrinsic Se vacancies render the pristine material an n-type degenerate semiconductor, Sb doping and Se-excess allow precise tuning of carrier concentration over a wide range (2.39 × 1019-4.81 × 1020 cm-3), enabling further optimization of electrical transport. At an optimal carrier concentration of 2.52 × 1020 cm-3, Ag0.5CdBi4.5Se8 achieves a peak thermoelectric ZT of 0.96 at 823 K, outperforming most previously reported pavonite derivatives. This work validates the utilization of the compound's intriguing multipolyhedral integration as a robust strategy to decouple electron-phonon transport, thereby providing insights for the rational design of high-performance thermoelectric materials.