Photodetector Applications Research Articles

Solvent-modulated preparation of lead-free Cs3Bi2I9polycrystalline film for high-performance photodetectors.

Lead-free cesium bismuth iodide (Cs3Bi2I9) perovskite exhibits extraordinary optoelectronic properties and attractive potential in various optoelectronic devices, especially the application for photodetectors. However, most Cs3Bi2I9photodetectors demonstrated poor detection performance due to the difficulty in obtaining high-quality polycrystalline films. Therefore, it makes sense to modulate the preparation of high-quality Cs3Bi2I9polycrystalline films and expand its applications. Here, a solvent-modulated method combining anti-solvent and precursor engineering has been developed to regulate the crystallization dynamics of Cs3Bi2I9. Anti-solvent treatment is to suppress the asynchronous separation out of CsI and BiI3due to significant differences in solubility, promoting uniform nucleation and limiting flake-like growth. Precursor engineering is synchronously used to modulate the subsequent nucleation growth dynamics. Due to the synergistic modulation, smooth and compact Cs3Bi2I9polycrystalline films with distinct grains and grain boundaries can be easily obtained. The as-prepared photodetector exhibits an excellent on/off ratio of 4.26×105as well as the detectivity up to 6.49×1010Jones at zero bias. And, the Cs3Bi2I9photodetector indicates excellent device stability, maintaining about 70% of the original performance after being stored for 400 hours in the air without encapsulation.&#xD.

Temperature‐Dependent Photoluminescence and Grain Size Control in a Prototypical Lead‐Free Bismuth Halide Perovskite

Lead‐free perovskites are non‐toxic solution‐processed semiconductors that promise applications in solar cells, light‐emitting diodes, and advanced photodetectors with broad and easily tunable spectral sensitivity. However, understanding excitonic properties and growth conditions are key for the development of efficient and stable materials. This study explores the temperature‐dependent photoluminescence (PL) and the influence of anti‐solvent on crystal size in methylammonium bismuth iodide (MA3Bi2I9), a prototypical bismuth‐based lead‐free perovskite. Using a one‐step spin‐coating method, low‐dimensional hexagonal MA3Bi2I9 crystals with controllable grain sizes ranging from 1.4 to 36 μm are developed, employing chlorobenzene as an anti‐solvent. Temperature‐dependent micro‐PL measurements reveal multi‐component PL emissions below 199 K and interestingly, below 144 K, bound excitonic recombination dominates the PL spectra. The observed free and bound exciton recombination peaks are consistent with the MA3Bi2I9 exciton binding energy of ≈340 meV reported in earlier studies. Observed temperature‐dependent PL spectra provide deeper insights into the excitonic properties of MA3Bi2I9, which have strong correlation with optoelectronic device performance, thereby providing a quick tool to assess as‐synthesized lead‐free perovskite films for defect‐site density and binding energy. Furthermore, the potential of concentration‐dependent anti‐solvent engineering in obtaining controllable bismuth perovskite crystal grain sizes for optoelectronic applications is underscored.

2D MXenes: Synthesis, Properties, and Applications in Silicon-Based Optoelectronic Devices.

MXenes, a rapidly emerging class of 2D transition metal carbides, nitrides, and carbonitrides, have attracted significant attention for their outstanding properties, including high electrical conductivity, tunable work function, and solution processability. These characteristics have made MXenes highly versatile and widely adopted in the next generation of optoelectronic devices, such as perovskite and organic solar cells. However, their integration into silicon-based optoelectronic devices remains relatively underexplored, despite silicon's dominance in the semiconductor industry. In this review, a timely summary of the recent progress in utilizing Ti-based MXenes, particularly Ti3C2Tx, in silicon-based optoelectronic devices is provided. The composition, synthesis methods, and key properties of MXenes that contribute to their potential for enhanced device performance are focused on. Furthermore, the latest advancements in MXene applications in silicon-based solar cells and photodetectors are discussed from fundamental and applied perspectives. Finally, the key challenges and future opportunities for the integration of MXenes in silicon-based optoelectronic devices are outlined.

Oxygen-modulated photoresponse in nickel oxide thin films for wide band gap photodetector application

Metal oxides, due to their wide band gap, are well suited for use in photodetectors as the active light-absorbing layer. While there have been extensive studies on n-type oxides, such as tungsten oxide and zinc oxide, there is relatively little work on the use of p-type oxides, such as nickel oxide (NiO), for photodetectors. Using these p-type oxides along with n-type conducting oxides to form heterojunctions can improve the detection capabilities by efficient separation of charge carriers. In this work, the photoresponse of a p-type NiO thin film, grown by room temperature reactive magnetron sputtering from a pure nickel target onto a conducting n-type indium-doped tin oxide (ITO) substrate, is investigated. Different ratios of oxygen to argon (10/45, 15/45, and 20/45) during sputtering are investigated, and the effect of oxygen concentration on the optical properties of the NiO film is studied, which helps in modulating the photoresponse of the developed detector. The O2/Ar ratio, with a value of 15/45, is found to perform better among the three ratios. For the corresponding photodetector, the current under illumination, is found to be nearly three orders of magnitude higher than the dark current, even at a very low applied voltage of 0.1 V. The calculated responsivity (at 0.012 A/W) is found to be the best among all three values. The device also has an excellent transient current response with a rise time of 0.5 s and a decay time of 1.4 s, which is the fastest transient behavior among all three ratio-based devices. The work paves the way for using metal oxide-based heterojunctions as wide band gap photodetectors.

Many-body perturbation-theory calculation of electronic and optical properties of β-phase Be3N2

Abstract The hexagonal β-phase of bulk Be3N2 is a wide band gap semiconductor with potential ultraviolet (UV) optoelectronics applications. Here, we have performed the first theoretical study of the electronic and optical properties of the β phase of Be3N2 considering many-body effects. In particular, we have obtained the electronic band structure and spectra of the dielectric function, complex refractive index and electron energy loss function. For the calculation of the band structure, both Density Functional Theory and G0W0 approximation plus Wannier interpolation of the bands have been applied. For the calculation of the optical spectra, we have employed both the independent particle approach as well as the formalism that incorporates many-body and excitonic effects, by applying G0W0 approximation and solving the Bethe-Salpeter equation (BSE). The results show, for instance, that the spectrum of the imaginary part of the dielectric function of β-Be3N2 has an anisotropic behavior. Even more, the material shows its highest absorption peak in the UV range, which makes it interesting due to its possible high-temperature photodetection applications. Also, in the visible energy range of the spectrum, the index of refraction along the z-axis (see figure 1) is predicted to be around 1.6, which is a high value for a solid.

Low-Temperature Growth of Centimeter-Sized 2D PdSe2 by Self-Limiting Liquid-Phase Edge Epitaxy.

Two-dimensional (2D) PdSe2 atomic crystals hold great potential for optoelectronic applications due to their bipolar electrical characteristics, tunable bandgap, high electron mobility, and exceptional air stability. Nevertheless, the scalable synthesis of large-area, high-quality 2D PdSe2 crystals using chemical vapor deposition (CVD) remains a significant challenge. Here, we present a self-limiting liquid-phase edge-epitaxy (SLE) low-temperature growth method to achieve high-quality, centimeter-sized PdSe2 films with single-crystal domain areas exceeding 30 μm. The SLE growth mechanism, clarified by theoretical calculations and time-of-flight secondary ion mass spectrometry (ToF-SIMS), reveals that hydrogen ions on the precursor surface inhibit vertical growth while promoting lateral growth. The as-grown PdSe2 few-layer exhibits a surface roughness of 1.20 nm and an average conductivity of 1.67 × 10-6 S/m, demonstrating their smoothness and uniformity. Temperature-dependent electrical measurements and transfer characteristic curves confirm the orthorhombic PdSe2's bipolar semiconductor behavior. The photodetector based on few-layer PdSe2 films exhibit excellent optoelectronic performance in the 405-1650 nm wavelength range, achieving a responsivity of 6262.37 A W-1, a detectivity of ∼1012 Jones under 1064 nm illumination, and a fast response time of 37.1 μs, making them highly suitable for broadband photodetection applications. This work provides valuable insights into the scalable synthesis of PdSe2 few-layers and establishes a foundation for the development of PdSe2-based integrated functional devices.

Surface modification unleashes light emitting applications of APbX3 perovskite nanocrystals.

Engineering the surface of metal halide perovskite nanocrystals (MHPNCs) is crucial for optimizing their optical properties, repairing surface defects, enhancing quantum yield, and ensuring long-term stability. These enhancements make surface-engineered MHPNCs ideal for applications in light-emitting devices (LEDs), displays, lasers, and photodetectors, contributing to energy efficiency. This article delves into an introduction to MHPNCs, their structure and types, particularly the ABX3 type (where A represents monovalent organic/inorganic cations, B represents divalent metal ions mainly Pb metal, and X represents halide ions), synthesis methods, unique optical properties, surface modification techniques using various agents (particularly inorganic molecules/materials, organic molecules, polymers, and biomolecules) to tune optical properties and applications in the aforementioned light-emitting technologies, challenges and opportunities, including advantages and disadvantages of surface-modified APbX3 MHPNCs, and a summary and future outlook. This article explores surface modification strategies to improve the optical performance of MHPNCs and aims to inspire advancements in light emitting applications. Importantly, the challenges and opportunities section of this article will illuminate the path to overcoming obstacles, providing invaluable insights for researchers in this field. This in-depth review explores the surface engineering of MHPNCs for light-emitting applications, highlighting their notable advantages and addressing ongoing challenges. By delving deep into various surface modification strategies, this article aims to revolutionize MHPNC-based light-emitting applications, setting a new benchmark in the field. This paves the way for revolutionary advancements, maximizing the capabilities of surface-engineered MHPNCs and heralding a transformative era in precise light-emitting research.

Opportunities and challenges of lead-free metal halide perovskites for luminescence.

Metal halide perovskites (MHPs) have been developed rapidly for application in light-emitting diodes (LEDs), lasers, solar cells, photodetectors and other fields in recent years due to their excellent photoelectronic properties, and they have attracted the attention of many researchers. Perovskite LEDs (PeLEDs) show great promise for next-generation lighting and display technologies, and the external quantum efficiency (EQE) values of polycrystalline thin-film PeLEDs exceed 20%, which is undoubtedly a big breakthrough in lighting and display fields. However, the toxicity and instabilities of lead-based MHPs remain major obstacles limiting their further commercial applications. The exploration and development of lead-free MHPs (LFMHPs) are regarded as the most facile strategies to solve these problems. Compared with lead-based perovskites, LFMHPs exhibit better stabilities and broadband emission. With continuous development of LFMHPs, their photoluminescence quantum yields (PLQYs) have reached 99%, facilitating their use as ideal emitters. In this review, the structures and features of LFMHPs are analyzed, and the preparation methods of LFMHPs with various structures and configurations are discussed. Then, the mechanisms and strategies for improving the emission performance of white LEDs based on LFMHPs are demonstrated. Finally, their challenges in commercial production and perspectives are prospected.

Improvement of UV-photodetector using nanoparticles synthesized by laser ablation in liquid: A review

Laser ablation in liquid (LAL) has emerged over the past decade as a powerful technique for the synthesis of nanomaterials and the fabrication of functional nanostructures. Its ability to tackle diverse challenges in nanotechnology highlights its growing significance. This review systematically evaluates recent advancements in LAL, focusing on the synthesis of nanocrystals and nanostructures. We begin by outlining the fundamental principles of the LAL process, with particular attention to critical laser parameters such as pulse wavelength, duration, pulse width, repetition rate, energy density (fluence) and the characteristics of the ablation medium. The review then explores the mechanisms that govern nanoparticle formation, with an emphasis on the control of particle shape and size during synthesis. Recent studies on LAL-generated nanomaterials, including bismuth oxide (Bi2O3), silver nanoparticles (Ag NPs) and germanium nanoparticles (Ge NPs), are discussed, highlighting their applications in ultraviolet photodetection. Key advantages of LAL, along with its limitations, are critically assessed, and potential strategies for overcoming these challenges are proposed. We conclude by identifying future research directions that will help advance the application of LAL in nanotechnology, particularly in the field of UV photodetectors.

Chemical Vapor Deposition Growth of Ternary Cu3PS4 Nanowires for Polarization‐Sensitive Photodetection

AbstractLow‐dimensional ternary materials with low‐symmetry structure have emerged as promising candidates for constructing polarization‐sensitive photodetectors. However, the photodetection applications of ternary materials remain challenging due to the limited varieties and the uncontrollable preparation. Herein, ternary Cu3PS4 nanowires with tunable thickness are successfully synthesized via chemical vapor deposition method. The grown Cu3PS4 nanowires present excellent structural anisotropy and strong in‐plane second‐order nonlinear optical anisotropy, as evidenced by angle‐resolved polarized Raman spectra and second harmonic generation measurements. Impressively, Cu3PS4‐based photodetector demonstrates a responsivity of 8.8 mAW−1, detectivity of 5.01 × 109 Jones, and photoresponse speeds with rise (decay) time of 1.5 (3.5) ms. Interestingly, the photodetector achieves polarization‐sensitivity photoresponse with an anisotropic ratio of 1.3 at 520 nm based on its inherent structural anisotropy and geometrical shapes. This work broadens the scope of synthesis strategy for various low‐dimensional ternary metal chalcohalide semiconductors and provides great opportunities for designing high‐performance and multifunctional optoelectronic devices.

Multi-Layer Absorber based on Plasmonic Resonances for Photovoltaic Applications at Visible Spectra

This paper introduces a broadband absorber based on a multilayered, double-cylindrical-shaped metamaterial, numerically characterized for its performance. The structure comprises four interacting layers that generate plasmonic resonances. CST microwave simulations were conducted to analyze its absorption characteristics. The results demonstrate that the proposed metamaterial absorber achieves 99% absorption at 847 nm frequency region and 98% absorption in the 500-1200 nm frequency region. Additionally, polarization dependency analysis confirms that the absorber performs as a perfect, polarization-independent absorber across the studied frequency range. It exhibits high absorption in both TE and TM modes and remains unaffected by polarization or variations in the incident angle. Numerical simulations reveal that the absorption performance is driven by a combination of Fabry–Perot resonance effects, localized surface plasmons, and propagating surface plasmons. In summary, the proposed metastructure demonstrates omnidirectional absorption, polarization independence, and wide-angle incident absorption. This design shows significant potential for applications in photodetectors, active optoelectronic devices, and sensors.

Near-Infrared Organic–Inorganic Copper Halide Film with Spectral Response over 1400 nm for Photodetector Application

Near-Infrared Organic–Inorganic Copper Halide Film with Spectral Response over 1400 nm for Photodetector Application

Alloying Ga2O3 with Fe2O3 on Corundum‐Structured rh‐ITO by Mist CVD and Its Demonstration of Photodetector and Photoelectrode Applications

Corundum‐structured α‐Ga2O3 is an ultrawide bandgap semiconductor with a bandgap of 5.3 eV and is actively investigated for applications in power electronics and optoelectronic devices. This study explores bandgap engineering of α‐Ga2O3 to broaden its application field. By alloying α‐Fe2O3, which has the same corundum structure as α‐Ga2O3, the bandgap can be tuned from 2.2 to 5.3 eV. This allows α‐Ga2O3 to be used as a visible‐light‐driven photocatalyst by narrowing its bandgap. Herein, (Ga, Fe)2O3 alloy thin films are grown on corundum‐structured indium tin oxide (rh‐ITO) electrodes for photocatalytic applications. X‐ray diffraction 2θ–ω measurements reveal that corundum‐structured α‐(Ga, Fe)2O3 thin films are grown on rh‐ITO electrodes with up to ≈20% Ga composition. At higher Ga compositions, orthorhombic ε‐GaFeO3 and amorphous Ga2O3 are observed on the rh‐ITO electrode. Photoresponsivity measurements using a photodetector structure confirm that the thin films exhibit visible light sensitivity upon alloying Fe2O3 with Ga2O3. Linear sweep voltammetry measurements indicate that the α‐(Ga, Fe)2O3 thin film grown on rh‐ITO can serve as a visible light‐driven photoelectrode. The findings contribute to the bandgap engineering of α‐Ga2O3 and its application in photocatalysis.

Strong Magneto‐chiroptical Effects through Introducing Chiral Transition‐metal Complex Cations to Lead Halide

The interplay between chirality with magnetism can break both the space and time inversion symmetry and have wide applications in information storage, photodetectors, multiferroics and spintronics. Herein, we report the chiral transition‐metal complex cation‐based lead halide, R‐CDPB and S‐CDPB. In contrast with the traditional chiral metal halides with organic cations, a novel strategy for chirality transfer from the transition‐metal complex cation to the lead halide framework is developed. The chiral complex cations directly participate the band structure and introduce the d‐d transitions and tunable magneto‐chiroptical effects in both the ultraviolet and full visible range into R‐CDPB and S‐CDPB. Most importantly, the coupling between magnetic moment of the complex cation and chiroptical properties is confirmed by the magneto‐chiral dichroism. For the band‐edge transition, the unprecedented modulation of +514% for S‐CDPB and ‐474% for R‐CDPB was achieved at ‐1.3 Tesla. Our findings demonstrate a novel strategy to combine chirality with magnetic moment, and provide a versatile material platform towards magneto‐chiroptical and chiro‐spintronic applications.

Strong Magneto-Chiroptical Effects through Introducing Chiral Transition-Metal Complex Cations to Lead Halide.

The interplay between chirality with magnetism can break both the space and time inversion symmetry and have wide applications in information storage, photodetectors, multiferroics and spintronics. Herein, we report the chiral transition-metal complex cation-based lead halide, R-CDPB and S-CDPB. In contrast with the traditional chiral metal halides with organic cations, a novel strategy for chirality transfer from the transition-metal complex cation to the lead halide framework is developed. The chiral complex cations directly participate the band structure and introduce the d-d transitions and tunable magneto-chiroptical effects in both the ultraviolet and full visible range into R-CDPB and S-CDPB. Most importantly, the coupling between magnetic moment of the complex cation and chiroptical properties is confirmed by the magneto-chiral dichroism. For the band-edge transition, the unprecedented modulation of +514 % for S-CDPB and -474 % for R-CDPB was achieved at -1.3 Tesla. Our findings demonstrate a novel strategy to combine chirality with magnetic moment, and provide a versatile material platform towards magneto-chiroptical and chiro-spintronic applications.

The low-temperature solution-process growth of c-axis aligned single crystalline ferroelectric SbSI nanorods arrays by nanosphere lithography for photovoltaic and photodetection applications

The low-temperature solution-process growth of c-axis aligned single crystalline ferroelectric SbSI nanorods arrays by nanosphere lithography for photovoltaic and photodetection applications

Structural, electronic, optical, magnetic, and mechanical properties of SmMnO3 perovskite with europium and yttrium doping: A first-principles study

This paper explores the impact of europium (Eu) and yttrium (Y) doping on the electronic, magnetic, optical, elastic, and structural properties of SmMnO3 perovskites using the Quantum ESPRESSO code. The cohesive energy and tolerance factor calculations revealed that the perovskite can maintain structural stability up to 25% doping of Eu and Y. Bandgap calculations suggest that when Eu and Y are doped, the energy bandgap of pure SmMnO3 decreases significantly from 2.72 to 0.47 and from 2.72 to 0.76 eV, respectively. Doped SmMnO3 exhibits a UV shift and increased intensity in the absorption coefficient, while the reflectivity peak decreases. These changes in optical properties and bandgap due to Eu and Y doping make SmMnO3 a promising material for advanced applications in photovoltaics, UV photodetectors, and optoelectronic devices. The ferromagnetic property and total magnetic moment of SmMnO3 are found to be increased by Eu doping. Meanwhile, the magnetic moment gets reduced by Y doping. Curie temperature calculations indicate that Eu doping increases the Curie temperature from 255.35 to 314.28 K, while Y doping reduces it from 255.35 to 187.69 K. These changes in magnetic moment and Curie temperature suggest that the doped material is suitable to be used in magnetic sensors and storage devices. The calculated elastic constants, Young’s modulus, shear modulus, Poisson’s ratio, and B/G ratio suggest that both pristine and doped compounds under study show a ductile behavior.

Gas-modulated optoelectronic properties of monolayer MoS2 for photodetection applications

Defects in monolayer MoS2 (M-MoS2) can cause complex electronic states that significantly affect its optical and electrical properties. Understanding and describing the impact of these defects, especially the role of sulfur vacancy (Vs) in M-MoS2 when integrating them into practical technologies, is crucial. However, a significant challenge exists in precisely controlling Vs generation in M-MoS2. This article presents an in situ defect engineering procedure for M-MoS2, considering the influence of external stimuli. We investigated how Vs changes and its impact on the optoelectronic characteristics of M-MoS2 after it is directly exposed to various gas environments. A photodetector device was fabricated, which exhibited an outstanding responsivity of 1.02 × 104 A/W, a detectivity of 1.2 × 1012 Jones, and an ultralow noise equivalent power of 1.56 × 10−18 W Hz−1/2. When the device is exposed to a reducing gas (H2S) environment, the performance increases by 136%, and in an oxidizing gas environment (NO2), it decreases by 68% in terms of responsivity due to a change in the concentration of Vs. We studied the photoresponse characteristics of the device by using Vs as the key parameter. This research contributes to the field of defect engineering in M-MoS2, expanding our knowledge of gas–surface interactions and assisting in producing highly sensitive optoelectronic devices.

Tellurium/Silicon based p-n photodiode for near infrared heterostructure photodetector applications

Tellurium/Silicon based p-n photodiode for near infrared heterostructure photodetector applications

Synthesis ZnO/ZnTe/Si thin films by Pulsed Laser Deposition for photodetector applications

Synthesis ZnO/ZnTe/Si thin films by Pulsed Laser Deposition for photodetector applications