Photoelectric Conversion Efficiency Research Articles

Flexible Semiconductor Electrode for in Vivo Neurochemical Recording in the Brain

AbstractNeural electrophysiological and neurochemical signals are crucial for understanding brain function and pathophysiology. Advances in neural interface technology have facilitated the capture of these signals via implantable microelectrodes. However, significant challenges persist in developing biocompatible interfaces, particularly in minimizing implantation‐induced tissue damage and preventing biofouling. Conventional noble metal electrodes, while widely used, have limitations in recording neurochemical dynamics and can cause tissue damage due to their rigid nature. Flexible semiconductor electrodes offer a promising alternative, due to their unique photoresponse and biocompatibility, but their photoelectric conversion efficiency is still insufficient, and fabrication methods are limited. This study introduces a novel flexible semiconductor fiber electrode fabricated via wet‐spinning, incorporating an n‐type ternary heterojunction (CdS/CdIn2S4/ZnIn2S4) to enhance photoelectric conversion efficiency. This electrode demonstrated uniform texture, reproducibility, and stability, with superior biocompatibility. Leveraging its photoresponsive properties, a neurochemical recording electrode is developed for real‐time monitoring of hydrogen sulfide levels in epileptic mice brains. This work provides a versatile platform for neurochemical signal acquisition and disease monitoring, offering significant potential for fundamental neuroscience research.

Near-Infrared Photodetection Using an Epsilon-Near-Zero Trapping Effect in Optimized Indium Tin Oxide Films.

This paper investigates the unique optical and electrical properties of indium tin oxide (ITO) materials to achieve hot-carrier-based near-infrared photoelectric conversion utilizing the epsilon-near-zero (ENZ) light-trapping effect. By precisely controlling carrier concentrations via rapid thermal annealing (RTA), we optimized the optical and electronic characteristics of ITO, resulting in tunable ENZ wavelengths ranging from 1370 to 1600 nm as annealing temperatures increased from 400 to 500 °C. We propose a prism-coupled planar Au-ITO-Si stack designed to achieve high light absorption and enhanced photoelectric conversion efficiency by leveraging the ENZ effect. The device demonstrates a distinct photoelectric response with a cutoff wavelength of 1600 nm, and the ENZ effect is evident in the photoelectric response spectrum. A phenomenological model was developed to explain the processes involved in hot carrier (HCs) generation, transport, and emission. This work highlights the tunability of the ENZ wavelength achievable through annealing treatments and explores its potential applications in near-infrared photoelectric conversion through an effective device design.

All-van-der-Waals Heterostructure of MoS2 Grating and InSe Flake for Spectrally Selective Polarization-Sensitive Photodetection in NIR Region.

Near-infrared (NIR) polarization photodetectors based on 2D materials hold immense potential for numerous optoelectronic applications. To enhance the weak light-matter interaction in 2D materials, integrating 2D semiconductors with metallic plasmonic nanostructures presents an effective solution. However, such metallic plasmonic nanostructures suffer from high optical loss in the infrared region owing to inherent Ohmic losses in metals. By developing an all-van-der-Waals (vdW) heterostructure of MoS2 grating and InSe flake, we demonstrate a spectrally selective polarization-sensitive NIR photodetector. Herein, bulk MoS2 gratings possess lower optical loss and stronger field confinement compared to conventional metallic gratings, leading to a higher photoelectric conversion efficiency. Additionally, the MoS2 grating supports both TE-excited guided-mode resonance at λ = 790 nm and TM-excited plasmonic resonance at λ = 960 nm. Such linear dichroism conversion behavior, with wavelength tunability, enables spectrally selective polarization-sensitive photodetection in the NIR region, achieving high dichroic ratios of 1.61 at 790 nm and 1.88 at 960 nm. Under 960 nm illumination, such MoS2 grating/InSe flake photodetector also demonstrates a responsivity of 28.5 A/W and a detectivity of 9.81 × 1012 Jones, respectively. In addition, with an ultrafast rise time of 195 ns and a decay time of 222 ns, this device represents the fastest photoresponse speed among InSe-based photodetectors reported to date. These results highlight the potential of 2D semiconductor gratings for high-performance all-vdW optoelectronics and nanophotonic devices.

Natural pigment-based dye-sensitized solar cells utilizing Caulerpa racemose and Gymnogongrus flabelliformis as photosensitizers

This research examines natural dyes' chemical and physical characteristics for potential use in dye-sensitized solar cells (DSSCs). Chlorophyll pigments were extracted from two macroalgae species, Caulerpa racemosa and Gymnogongrus flabelliformis, and analyzed using absorbance spectroscopy, band gap energy calculations, and dye-sensitized solar cell performance evaluation. Fourier Transform Infrared (FTIR) characterisation was used to identify the pigments contained in the dye. The absorbance spectra of chlorophyll pigments extracted from both macroalgae species showed broad peaks at 400–800 nm wavelengths, with Gymnogongrus flabelliformis showing the highest absorbance peak at 403 nm. The redox potential analysis for both macroalgae species showed energy gaps (HOMO/LUMO) of 1.3 eV, 1.4 eV, 2.3 eV, and 2.4 eV, respectively, indicating that these natural dyes are suitable for use in DSSC applications. DSSC devices were fabricated using components such as liquid electrolyte, mesoporous titanium dioxide (TiO₂) photoelectrode, reduced graphene oxide (rGO) as counter electrode, and ITO glass as conductive substrate. Meanwhile, to evaluate how well the photovoltaic system worked, we looked at short-circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF), and overall photoelectric conversion efficiency (η). The results showed that the highest performance for Gymnogongrus flabelliformis was Jsc 0.041 mA/cm², Voc 0.28 V, FF 0.239, and η 0.020%, while the highest performance of Caulerpa racemosa was Jsc 0.023 mA/cm², Voc 0.46 V, FF 0.244, and η 0.019%. These findings indicate the potential for using and developing natural dyes derived from these two macroalgae species in DSSC technology. This research offers insight into the feasibility of marine-derived pigments as a sustainable and environmentally friendly alternative for photovoltaic applications.

Lattice coherency engineering trigger rapid charge transport at the heterointerface of Te/In2O3@MXene photocatalysts for boosting photocatalytic hydrogen evolution.

Lattice coherency engineering trigger rapid charge transport at the heterointerface of Te/In2O3@MXene photocatalysts for boosting photocatalytic hydrogen evolution.

Polarity-Switchable Dual-Mode Photoelectrochemical Cancer Marker Immunoassay Based on a Metal-Organic Framework@Nitrogen-Doped Graphdiyne Heterojunction.

A photocurrent polarity-switching photoelectrochemical (PEC) assay has been used for its anti-interference ability and superior accuracy compared to a conventional PEC measuring system. In this work, an ultrasensitive photocurrent polarity-switchable assay was established for sensitive prostate-specific antigen (PSA) detection based on a novel metal-organic framework (MOF) and graphdiyne@polyaniline (GDY@PANI)-sensitized structure as a photoactive material. The nitrogen-doped carbon nanolayers wrapped around graphdiyne and a zinc-based MOF were synthesized via a hydrothermal method. As an excellent photoactive material, the type II heterostructure (MOF/GDY@PANI) not only reduced the recombination of generated electron-hole pairs but also resulted in a significant increase in photoelectric conversion efficiency. Furthermore, its photocurrent was 4.6-fold higher than that of GDY@PANI and 37-fold higher than the proposed MOF. The integrated MOF/GDY@PANI/antibody (Ab) glassy carbon photoelectrode (GCE) was used as a PEC immunosensor for PSA detection (signal-off mode) and exhibited a wide linear dynamic range from 0.1 fg/mL to 10 pg/mL and a limit of detection of 0.05 fg/mL. The GCE modified with MOF and primary antibody (Ab1) (GCE/MOF/Ab1) produced a cathodic photocurrent, and in the presence of PSA, after the introduction of GDY@PANI-labeled-secondary antibody (Ab2) onto the surface of GCE/MOF/Ab1 and formation of an immunocomplex, the photocurrent amplified and switched to an anodic current. Due to high photoelectric conversion efficiency and good polarity-switching ability of GDY@PANI, the proposed immunosensor presented a turn-on photoelectrochemical performance for PSA detection at a wide linear range from 0.1 to 10 pg/mL and ultralow detection limit of 0.03 fg/mL. Compared to signal-off mode, the sensitivity increased 2-fold and the effect of interferences produces more reliable results due to photocurrent switching, and its effectiveness was evaluated against an enzyme-linked immunosorbent assay (ELISA) using spiked real human serum samples. The positive and promising outcomes achieved by the proposed immunosensor imply that the developed platform has the potential to serve as an excellent enzyme-free photoanode immunosensor for early cancer diagnosis and therapeutic monitoring.

Dramatically Prolonged Photoexcited Carrier Lifetimes in Group-III Monochalcogenide Heterostructures through Stacking Modulation.

Modulating the carrier dynamics to achieve the effective separation of photoexcited carriers is crucial for enhancing photoelectric conversion efficiency and advancing high-performance optoelectronic devices. A prototype group-III monochalcogenide heterostructure, GaSe/GaTe, has been proposed to exhibit a superior light-harvesting capability and highly tunable charge separation characteristics via nonadiabatic molecular dynamics (NAMD) simulations. The significant influence of stacking patterns on carrier dynamics is revealed, with electron (hole) transfer occurring within 97 (40) to 390 (126) fs, while the carrier lifetime is dramatically prolonged from 12 to 213 ns, facilitating effective electron-hole (e-h) pair separation. Notably, the AA' and A'A stacking configurations demonstrate remarkably extended carrier lifetimes of 213 and 161 ns, respectively, exceeding those observed in other 2D heterostructures. The weak nonadiabatic coupling and low-frequency phonon vibrational modes suppress e-h recombination, leading to a prolonged carrier lifetime. These findings offer atomic insights into stacking-dependent carrier dynamics, advancing 2D optoelectronic device design.

Development and Future Prospects of Perovskite Solar Cells

Perovskite solar cells (PSCs), as a representative of third-generation photovoltaic technology, have emerged as a research hotspot for overcoming the performance limitations of traditional silicon-based cells due to their high photoelectric conversion efficiency, low cost, and structural design flexibility. This paper systematically reviews breakthrough advancements in PSCs over the past five years: the efficiency of single-junction cells has risen from 25% to 26.9%, while tandem cells have achieved efficiencies exceeding 33.89%. Through material engineering (compositional regulation, defect passivation), interface optimization (alloyed electrodes, passivation layers), and encapsulation techniques (flexible stress-release structures, eco-friendly recycling), the stability under damp-heat conditions (T80 lifespan exceeding 2,000 hours) and environmental adaptability of PSCs have been significantly enhanced. Concurrently, advancements in large-area printing and vapor deposition technologies have accelerated industrialization (module efficiency of 28.6%, GW-scale production lines established) However, challenges such as lead toxicity concerns, insufficient long-term stability, and efficiency degradation in scaled-up production remain critical barriers to commercialization. Looking ahead, the development of lead-free materials, quantum dot-based triple-junction architectures, and closed-loop recycling systemscould propel PSCs toward a 40% efficiency target, positioning them as a core driver of photovoltaic industry innovation under the "Dual Carbon" strategy.

Enhanced Long-Term Stability of Perovskite Solar Cells Employing a Benzodithiophene Derivative-Based Dopant-Free Hole Transporting Layer.

Perovskite solar cell (PSC) is characterized by high photoelectric conversion efficiency (PCE) and low material cost compared to the silicon solar cell that has already been commercialized. Many researchers are conducting various studies to improve efficiency and stability. To increase power conversion efficiency, hole transporting materials (HTMs) are one of the most important factors for achieving high performance in PSCs. HTMs exhibit an important role in PSCs to transfer the positive charges in between perovskite and counter electrodes. Among the various HTMs, Spiro-OMeTAD has been widely used in PSCs. However, due to its reliance on additives to enhance hole mobility, Spiro-OMeTAD suffers from degradation issues that compromise its long-term stability. So, it is necessary to develop new HTMs to replace Spiro-OMeTAD for their low stability and expensiveness in future application of PSCs. Therefore, we designed and synthesized the materials named PEH-23 and PEH-24 incorporating dialkoxyphenyl and dialkoxybenzodithiophene. As the conjugation length increases, the material demonstrates improved stability, suggesting its potential as an effective HTM with long-term reliability.

The influence of the position and quantity of thiophene or acetylene groups on the photoelectric properties of dye-sensitized solar cells.

The influence of the position and quantity of thiophene or acetylene groups on the photoelectric properties of dye-sensitized solar cells.

Iron oxides semiconductor minerals photocatalysis reduce methane fluxes in paddy soils.

Iron oxides semiconductor minerals photocatalysis reduce methane fluxes in paddy soils.

Tailoring Photophysical Processes of Er3+‐Doped Gd3Ga5O12 Garnets for Enhanced Photoluminescence via Al3+ Ion Preference Substitution

ABSTRACTRare‐earth ion‐doped garnets with excellent luminescent properties show great potential for temperature sensing, displays, and nondestructive detection. However, their limited luminescent modes and low photoluminescence quantum yields (PLQY) restrict further applications. In this study, we synthesized Al3+, Er3+‐co‐doped Gd3Ga5O12 garnets with multimode luminescence via a high‐temperature solid‐state method. Notably, the preferential substitution of Al3+ ion at octahedral‐coordinated GaI sites significantly enhanced the charge density and electron transition probability, achieving a PLQY enhancement of the down‐shifting luminescence from 35.1% to 68.5%. Al3+ ion also influences electron relaxation during up‐conversion luminescence, resulting in a color shift from red to yellow to green. Additionally, Al3+ incorporation increased the photoelectric conversion efficiency of light‐emitting diodes from 2.9% to 6.3% and improved temperature sensing sensitivity from 2.7% to 5.1% K⁻¹. This work provides new insights into the photophysical mechanisms and underscores the key role of Al3+ ion in optimizing the optical properties of garnet‐based materials.

Study on Optical Response Behavior and Mechanism of Silicon-based Micro-nano Cross-scale Surface Structure

At present, many new materials and devices have been applied to optical functional surfaces, and it has become one of the research hotspots to improve the efficiency of light absorption and photoelectric conversion by changing the micro-nano structure of their surfaces. In view of this, the optical response characteristics of silicon (Si)-based micro-nano cross-scale surface structure are studied in this paper, and the cross-scale surface structure of Si-based micro/nano-pillar composite Al nanoparticles is constructed. The light intensity distribution and absorption rate evolution law of surfaces with different geometric characteristics are studied by the finite difference time domain method. The results show that when the wavelength is 500 nm, the maximum absorption rate of the cross-scale surface structure of Si-based micro-nano column composite Al nanoparticles reaches 84.6%, which is 1.69 times that of the unused surface structure, which greatly improves the optical absorption performance. The surface light intensity distribution shows that the surface structure of Si-based micro-nano columns and Al nanoparticles dominates the improvement of absorption efficiency. The cross-scale surface structure of Al nanoparticles compounded with Si-based nano-meter pillars can improve the light absorption performance and the photoelectric conversion efficiency, which has a wide application prospect in the fields of optical storage and photoelectric detection.

Gradient Doping Strategy for Sn─Pb Mixed Perovskite Solar Cells with High Efficiency and Stability.

Sn─Pb hybrid perovskite has attracted more attention due to its ideal bandgap and excellent photoelectric properties. However, easy oxidation and poor crystallinity caused by the introduction of Sn2+ have become two major problems. In this study, Sn2+ is doped in the Pb-based perovskite to prepare high crystalline Sn─Pb mixed perovskite with larger grain size by using the solvent engineering technique and the cooperation optimization with HCOOH. The reducibility of HCOOH and its inhibition of deprotonation significantly prevent the oxidation of Sn2+ and the decomposition of A-site cations. The experimental and theoretical results show that the interactions between HCOOH and Sn2+ and Pb2+, which reduce the defect density and improve the crystallinity and stability of the film with excellent photoelectric properties. In addition, the compact SnO2 prepared by atomic layer deposition as electronic transformation layer to further improve the stability of devices. The photoelectric conversion efficiency of the Sn─Pb hybrid perovskite solar cells (PSCs) prepared by the dopant growth method can reach 21.53% and the stability is significantly better than that of the Sn─Pb PSCs prepared by the traditional method.

Interaction Mechanism and Oscillation Characteristics of Grid-Connected Concentrating Solar Power–Battery Energy Storage System–Wind Hybrid Energy System

Solar thermal concentrating solar power (CSP) plants have attracted growing interest in the field of renewable energy generation due to their capability for large-scale electricity generation, high photoelectric conversion efficiency, and enhanced reliability and flexibility. Meanwhile, driven by the rapid advancement of power electronics technology, extensive wind farms (WFs) and large-scale battery energy storage systems (BESSs) are being increasingly integrated into the power grid. From these points of view, grid-connected CSP–BESS–wind hybrid energy systems are expected to emerge in the future. Currently, most studies focus solely on the stability of renewable energy generation systems connected to the grid via power converters. In fact, within CSP–BESS–wind hybrid energy systems, interactions between the CSP, collection grid, and the converter controllers can also arise, potentially triggering system oscillations. To fill this gap, this paper investigated the interaction mechanism and oscillation characteristics of a grid-connected CSP–BESS–wind hybrid energy system. Firstly, by considering the dynamics of CSP, BESSs, and wind turbines, a comprehensive model of a grid-connected CSP–BESS–wind hybrid energy system was developed. With this model, the Nyquist stability criterion was utilized to analyze the potential interaction mechanism within the hybrid system. Subsequently, the oscillation characteristics were examined in detail, providing insights to inform the design of the damping controller. Finally, the analytical results were validated through MATLAB/Simulink simulations.

Peering into interfaces in perovskite solar cells: a first-principles perspective

Over the past decade, perovskite solar cells (PSCs) have experienced a rapid development. The remarkable increase in the photoelectric conversion efficiency demonstrates great promise of halide perovskites in the field of photovoltaics. Despite the excellent photovoltaic performance, further efforts are needed to enhance efficiency and stability. Interfacial engineering plays a crucial role in enhancing the efficiency and stability of PSCs, enabling champion cells to sustain a power conversion efficiency above 26% for over 1000 h. As a powerful theoretical tool for characterizing interfaces in PSCs, first-principles calculations have contributed to understanding interfacial properties and guiding the materials design. In this Perspective, we highlight the recent progress in theoretically profiling the interfaces between halide perovskites and other materials, focusing on the effects of energy band alignment and electronic structure on the carrier transport at the interfaces. These first-principles calculations help to reveal the atomic and electronic properties of the interfaces, and to provide important theoretical guidance for experimental research and device optimization. We also analyze potential strategies to enhance carrier separation and transport in PSCs, and discuss the challenges in accurate modeling interfaces in PSCs, which will help to understand the fundamental physics of interfaces in PSCs and to guide their further optimization.

Preparation and study of perovskite solar cells with titanium–tin alloy-based electron transport layers

Abstract The electron transport layer (ETL) plays a fundamental role in perovskite solar cells (PSCs), where ETL extracts and transports photogenerated carriers and influences the photoelectric conversion efficiency. In this context, this paper develops a novel design for the titanium–tin alloy-based ETL. Experimental results show that the efficiency of power conversion efficiency (PCE) can be maximized (i.e. 16.42%) when the molar ratio of titanium dioxide (TiO2) to tin oxide (SnO2) doping reaches 7:1. Moreover, in this case, the PSC device can maintain the 81.5% of the maximum efficiency over 42 d. Therefore, the proposed scheme can significantly improve the electron mobility and surface morphology in ETL, thereby achieving superior performance compared with prior schemes.

Advanced solar photo-Fenton-like process with directly growing nano-heterojunctions on graphite fiber felt for phenolic wastewater treatment: Synergistically expand the pH activity range and facilitate the Fe(III)/Fe(II) cycle.

Advanced solar photo-Fenton-like process with directly growing nano-heterojunctions on graphite fiber felt for phenolic wastewater treatment: Synergistically expand the pH activity range and facilitate the Fe(III)/Fe(II) cycle.

Magnetic Field Modulation Effect of Photoelectric Properties in Dye-sensitized Solar Cells with La0.67(Ca,Ba)0.33MnO3 as Counter Electrodes.

In recent years, many semiconductor materials with unique band structures have been used and also pursued patent protection as Pt counter electrode (CE) substitutes for dyesensitized solar cells (DSSCs), which makes the photoelectric properties of DSSCs possible to be modulated by electric field, magnetic field, and light field. In this work, La0.67(Ca,Ba)0.33MnO3 (LCBMO) thin film is employed to act as CE in DSSCs. The experimental results indicate that short-circuit current density and photoelectric conversion efficiency present better stability when applying an external magnetic field to the DSSCs. Furthermore, both the exchange current density (J0) and limit diffusion current density (Jlim) are largely enhanced by an external magnetic field. J0 increases from -0.51 mA·cm-2 to -0.65 mA·cm-2, and Jlim increases from 0.2 mA·cm-2 to 0.3 mA·cm-2 when applying a magnetic field of 0.25 T. The fitting results of the impedance test verify that the magnetic field reduces the value of Rct. Both magnetic-field enhancing catalytic activity and CMR effect jointly promote the increase of photocurrent and finally improve the photovoltaic effect in DSSCs.

A novel photoelectrochemical biosensor for sensitive detection of nucleic acids based on recombinase polymerase amplification and 3D-array titania nanorods.

A novel photoelectrochemical biosensor for sensitive detection of nucleic acids based on recombinase polymerase amplification and 3D-array titania nanorods.