- 标题
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- 实验方案
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Self-Patterned CsPbBr3 Nanocrystals for High-Performance Optoelectronics
摘要： All-inorganic lead halide perovskites are promising materials for many optoelectronic applications. However, two issues that arise during device fabrication hinder their practical use, namely inadequate continuity of coated inorganic perovskite films across large areas and inability to integrate these films with traditional photolithography due to poor adhesion to wafers. Herein, for the first time, to address these issues, we show a room-temperature synthesis process employed to produce CsPbBr3 perovskite nanocrystals with two-dimensional (2D) nanosheet features. Due to the unique properties of these 2D nanocrystals, including the 'self-assembly' characteristic, and 'double solvent evaporation inducing self-patterning' strategy are used to generate high-quality patterned thin films in selected areas automatically after-drop-casting, enabling fabrication of high-performance devices without using complex and expensive fabrication processing techniques. The films are free from micro-cracks. In a proof-of-concept experiment, photodetector arrays are used to demonstrate the superior properties of such films. We provide evidence of both high responsivity (9.04 A/W) and high stability across large areas. The photodetectors fabricated on flexible substrate exhibit outstanding photo-response stability. Advanced optical and structural studies reveal the possible mechanism. Our simple and cost-effective method paves the way for the next-generation nanotechnology based on high-performance, cost-effective optoelectronic devices.
关键词： photodetector,Self-assembly,self-patterning,two-dimensional nanosheet,perovskite
更新于2025-09-23 15:23:52
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Wafer-scale Fabrication of Nitrogen-doped Reduced Graphene Oxide with Enhanced Quaternary-N for High-Performance Photodetection
摘要： We demonstrated a simple and scalable fabrication route of nitrogen-doped reduced graphene oxide (N-rGO) photodetector on 8-inch wafer-scale. The N-rGO was prepared through in-situ plasma-treatment in an acetylene-ammonia atmosphere to achieve n-type semiconductor with substantial formation of quaternary-N substituted into the graphene lattice. The morphology, structural, chemical composition and electrical properties of the N-rGO was carefully characterized and being used for the device fabrication. The N-rGO devices were fabricated in a simple metal-semiconductor-metal (MSM) structure with unconventional metal-on-bottom configuration to promote high-performance photodetection. The N-rGO devices exhibited enhanced photoresponsivity as high as 0.68 A W?1 at 1.0 V, which is about two orders of magnitude higher compared to a pristine graphene and wide-band photo-induced response from visible to near-infrared (NIR) region with increasing sensitivity in the order of 785 nm, 632.8 nm and 473 nm excitation wavelengths. We also further demonstrated a symmetric characteristic of photo-induced response to any position of local laser excitation with respect to the electrodes. The excellent features of wafer-scale N-rGO devices suggest a promising route to merge the current silicon technology and two-dimensional materials for future optoelectronic devices.
关键词： photodetector,plasma treatment,quaternary-N,wafer-scale fabrication,Nitrogen-doped reduced graphene oxide
更新于2025-09-23 15:23:52
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Barrier engineering for HgCdTe unipolar detectors on alternative substrates
摘要： Delta-doped layers together with compositionally grading have been utilized to get nBn configurations for the HgCdTe material system in all the short-wave (SWIR), medium-wave (MWIR) and long-wave (LWIR) infrared bands. Shockley Read Hall (SRH), trap-assisted tunneling (TAT), Auger and radiative recombination mechanisms have been included in the analyses and strong suppression of SRH and TAT currents have been demonstrated with the designed structures. This methodology is especially useful when the carrier lifetime is limited due to alternative substrate usage. No degradation in photo-response has been observed as adjusting the valence band offset is quite flexible with the delta-doped nano-layers and the valence band barrier can be completely removed. Calculations have been performed for 1–3 μs lifetime targeting the alternative substrate applications and up to 60 degrees of increase in the operation has been shown to be possible.
关键词： HgCdTe,nBn,Photodetector,Barrier structures
更新于2025-09-23 15:23:52
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Systematic investigations on the effect of prolong UV illumination on optoelectronic properties of ZnO honeycomb nanostructures
摘要： Herein, the effect of prolong UV illumination over ZnO optoelectronic characteristics has been investigated. The photoluminescence analysis has shown significant enhancement in deep level emission (DLE) after sample being exposed to UV radiations. The formation of photo-induced oxygen vacancies (VO) over the ZnO surface was found to be responsible for such noteworthy enhancement in DLE. The observed phenomenon was further utilized for controlled incorporation of VO in ZnO via UV illumination, towards obtaining optimal device performance. The UV treated photo-detector has shown significantly high photo-responsivity and photo-sensitivity in the deep UV region.
关键词： Zinc oxide,Honeycomb structure,Deep UV photodetector,XRD,Lattice defects
更新于2025-09-23 15:23:52
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Highly Sensitive Polarization Photodetection Using a Pseudo-One-Dimensional Nb <sub/> (1– <i>x</i> ) </sub> Ti <sub/><i>x</i> </sub> S <sub/>3</sub> Alloy
摘要： Low-symmetry layered two-dimensional (2D) materials with strong in-plane optical anisotropy can potentially be applied for polarization photodetection. This is especially true for those 2D materials with a direct bandgap, who can efficiently absorb light with specific axial polarization. However, discovering such new anisotropic 2D materials with direct band structure is still extremely challenging. Here, we fabricate a photodetector using a pseudo-one-dimensional (pseudo-1D) Nb(1-x)TixS3 alloy device, and demonstrate that it is highly sensitive to the polarized light due to the strong in-plane optical anisotropy and direct bandgap of the alloy by combining the angle-resolved polarization Raman spectroscopy (ARPRS), azimuth-dependent reflectance difference microscopy (ADRDM), polarization-dependent absorption spectroscopy (PDAS), and hybrid functional theory calculations. As a consequence, the polarization photodetector of the Nb(1-x)TixS3 alloy shows a large photocurrent anisotropic ratio and a high photoresponse. The choice of low-symmetry layered pseudo-1D Nb(1-x)TixS3 alloy in polarization photodetection might open up new functionalities for novel optoelectronic device applications.
关键词： low-symmetry structure,in-plane optical anisotropy,pseudo-one-dimensional materials,Nb(1-x)TixS3 ternary alloy,polarization-sensitive photodetector
更新于2025-09-23 15:23:52
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Hydrothermal growth and their optoelectronic device application of CuI nanostructure
摘要： Cuprous iodide (CuI) was grown on the Si (100) and Cu films/Si(100) substrate by hydrothermal reaction and hydrothermal evaporation methods. It has been found that all the hydrothermal methods. Different nanostructured CuI have been obtained using photoluminescence (PL) character of nanostructured CuI, the origin of different PL emissions and the different growth mechanisms have been discussed. Then, the nanostructured CuI films have a γ phase with polycrystalline structure. Having analyzed the short-wavelength optoelectronic devices [1-3]. Moreover, CuI possesses some superior properties, such as high hole mobility, excellent p-type conductivity and high transmissivity. These properties make CuI a promising material for applications in the photodetectors [2], transparent conducting films [4], solid-state dye solar cells [5-8] and light-emitting diode [9]. Though different fabrication methods have been used to synthesize CuI [10-14], it is still a challenge to grow epitaxial thin films of CuI with high quality due to the lack of lattice-matched substrates. Commonly for the mismatch substrate, interface strain can be much easier accommodated in the nanostructure than the films. Furthermore, owing to their large surface-to-volume ratio, nanostructured CuI can exhibit special advantage in devices applications, especially for the solid state electrolyte in solar cell and hole transport layer in photodetector applications [1-3]. Here, nanostructured CuI have been synthetized on the Si (100) substrate by hydrothermal methods. The structure and optical properties have been investigated. Photodetector based on n-ZnO/p-CuI heterojunction have been fabricated and the photoelectric properties are also discussed.
关键词： photodetector,CuI,photoluminescence,hydrothermal
更新于2025-09-23 15:23:52
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Two-Dimensional Non-Layered Selenium Nanoflakes: Facile Fabrications and Applications for Self-Powered Photo-Detector
摘要： Two-dimensional (2D) materials exhibit many interesting properties, but most of two-dimensional materials are exfoliated from layered bulk materials, limiting the development of 2D material group. Recently, non-layered 2D materials have aroused a great attention due to their excellent catalysis performance, favored compatibility with silicon substrates and highly chemically active. With high photoconductivity, high responsivity and fast response time, non-layered selenium (Se) exhibits important applications in the field of optoelectronics. In this work, we use a simple liquid phase exfoliation method to fabricated 2D Se nanoflakes from bulk Se which possesses unique chain structure. The thickness of 2D Se nanoflakes was measured to be in the range of 5-10 nm. As-fabricated Se nanoflakes was used in a photodetector by photoelectrochemical (PEC) method, showing a high photocurrent density (1.28 μA/cm2) and photoresponsivity (10.45 μA/W). In addition, the long-term photoelectric measurements indicate that the 2D Se-based photodetector has good time and cycle stability. Our results show that 2D Se have promising potential in liquid-based photo-detectors.
关键词： 2D selenium,photoelectrochemical photodetector,nonlayered 2D materials
更新于2025-09-23 15:22:29
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Preparation of radial ZnSe-CdS nano-heterojunctions through atomic layer deposition method and their optoelectronic applications
摘要： Radial 1-D nano-heterojunctions have distinct optoelectronic properties. However, their complex fabrication process is still the bottleneck of device applications. Herein, a facile atomic layer deposition (ALD) method was used to coat a polycrystalline CdS thin film with high uniformity and controllable thickness on the surface of the as-synthesized p-type ZnSe nanowires, for fabricating radial 1-D ZnSe-CdS nano-heterojunctions. The nano-heterojunctions exhibited excellent optoelectronic properties. Under blue/violet light, the nano-heterojunctions obtained a response radio of ~5 × 10^3, a responsitivity of ~1.43 A/W, a gain of ~3.78 and a detectivity of ~0.57 × 10^12 cmHz^{1/2}W^{-1} at zero bias. Furthermore, the nano-heterojunction also showed obvious photovoltaic characteristic with a power conversion efficiency of ~0.96%. This method is expected to play an important role in nano-heterojunction construction and their device applications.
关键词： ZnSe,CdS,Photovoltaic,Nano-heterojunction,Atomic layer deposition,Photodetector
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 15th International Conference on Group IV Photonics (GFP) - Cancun (2018.8.29-2018.8.31)] 2018 IEEE 15th International Conference on Group IV Photonics (GFP) - Novel Quick and Precise Method for Evaluating Optical Characteristics
摘要： We describe a new test element and method for evaluating optical characteristics such as a propagation loss. The test element is simply composed of a grating coupler, an interferometer, and an integrated photodetector. The propagation loss is accurately derived by a few elements. This method has potential for drastically reducing measurement time in wafer-level inspection.
关键词： on-wafer testing,propagation loss,grating coupler,photodetector
更新于2025-09-23 15:22:29
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Large area SiC-UV phothodiode for spectroscopy portable system
摘要： In this work, we present the extensive characterization of large area Silicon Carbide based UV sensors candidate for outdoors spectroscopic applications of gas or liquid. The proposed SiC Schottky devices exhibit dark current density of 0.12 nA/cm2 @ 15 V, a 0.12 A/W responsivity @ 300 nm, optimal visible blindness and switching time of ~ 190 ns. Effects of temperature on the sensor performance, of crucial interest for outdoors applications, are also examined in the range from -20 °C to 90 °C.
关键词： optical sensor,Large area UV photodetector,Schottky diode,SiC detector
更新于2025-09-23 15:22:29