- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Inverse Growth of Large Grain Size and Stable Inorganic Perovskite Micro-Nanowire Photodetectors
摘要： Control of the forward and inverse reactions between perovskites and precursor materials is key to attaining high quality perovskite materials. Many techniques focus on synthesizing nanostructured CsPbX3 materials (e.g., nanowires) via a forward reaction (CsX + PbX2 → CsPbX3). However, lower solubility of inorganic perovskites and complex phase transition make it difficult to realize the precise control of composition and the length of nanowires using the conventional forward approach. Herein, we report a self-assembly inverse growth of CsPbBr3 micro-nanowires (MWs) (CsPb2Br5 → CsPbBr3 + PbBr2 ↑) by controlling phase transition from CsPb2Br5 to CsPbBr3. Two-dimensional (2D) structure of CsPb2Br5 serves as nucleation sites to induce the initial CsPbBr3 MW growth. Also, phase transition allows crystal rearrangement and slows down the crystal growth, which facilitates the MW growth of CsPbBr3 crystals along the 2D planes of CsPb2Br5. A CsPbBr3 MW photodetector constructed based on the inverse growth shows a high responsivity of 6.44 A W-1 and detectivity of ~1012 Jones. Larger grain size, high crystallinity and bigger thickness can effectively alleviate the decomposition/degradation of perovskites, which leads to storage stability over 60 days in moisture (45% relative humidity) and operational stability over 3000 min under illumination (400 nm, ~20.06 mW cm-2).
关键词： inverse growth,photodetector,operational stability,inorganic perovskite,micro-nanowire
更新于2025-09-19 17:13:59
-
All-optical InAsP/InP nanowire switches integrated in a Si photonic crystal
摘要： We report the successful demonstration of all-optical switching using a sub-wavelength InP/InAsP nanowire integrated in a silicon photonic crystal at telecommunication wavelengths. In this work, we employed two different hybrid nanowire cavities based on an air-trench in photonic crystals. These hybrid cavities have the advantages of both material functionality of III-V material and the low propagation loss of the silicon waveguide. The nanowire induced line-defect photonic crystal cavity shows a Q-factor of 25000, higher than the hybrid systems we previously demonstrated. The switching time is 150 ps, which is among the fastest nanowire switches reported. We found that the switching time was clearly dependent on the Q-factor. From measurements performed while changing pump power, we have estimated the switching energy to be a few hundred femtojoules. This value is lower than that of a reference silicon photonic crystal cavity without a nanowire and an air trench under the same pumping condition. This indicates that the InP/InAsP nanowire integrated in a silicon photonic crystal has potential to contribute to reducing the switching energy.
关键词： all-optical switch,AFM manipulation,nanophotonics,photonic crystal,nanowire,photonic integrated circuits
更新于2025-09-19 17:13:59
-
<i>In situ</i> passivation of GaAsSb nanowires for enhanced infrared photoresponse
摘要： Surface passivation of semiconductor nanowires (NWs) is important for their optoelectronic properties and applications. Here, the in situ passivation effect of an epitaxial InP shell and the corresponding photodetector performance is experimentally studied. Compared with the unpassivated GaAsxSb1-x core-only NWs, the GaAsxSb1-x/InP core/shell NWs have shown much stronger photoluminescence and cathodoluminescence intensities. Correspondingly, the fabricated single GaAsxSb1-x/InP core/shell NW photodetector shows a responsivity of 325.1 A/W (@ 1.3 μm and 1.5 V) that is significantly enhanced compared to that of single GaAsxSb1-x core-only NW photodetectors (143.5 A/W), with a comparable detectivity of 4.7×1010 and 5.3×1010 cm√Hz/W, respectively. This is ascribed to the enhanced carrier mobility and carrier concentration by the in situ passivation, which lead to both higher photoconductivity and dark-conductivity. Our results show that in situ passivation is an effective approach for performance enhancement of GaAs1-xSbx NW based optoelectronic devices.
关键词： semiconductor,surface passivation,infrared photodetector,GaAsSb,MOCVD,InP,nanowire
更新于2025-09-19 17:13:59
-
Recent progress on infrared photodetectors based on InAs and InAsSb nanowires
摘要： In recent years, quasi-one-dimensional semiconductor nanowires have attracted numerous research interests in the field of optoelectronic devices. Indium arsenide (InAs) nanowire, an III-V compound semiconductor structure with a narrow bandgap, shows high electron mobility and high absorption from the visible to the mid-wave infrared (MWIR), holding promise for room-temperature high-performance infrared photodetectors. Therefore, the material growth, device preparation, and performance characteristics have attracted increasing attention, enabling high sensitivity InAs nanowire photodetector from the visible to the MWIR at room temperature. This review starts by discussing the growth process of the low-dimensional structure and elementary properties of the material, such as the crystalline phase, mobility, morphology, surface states, and metal contacts. Then, three solutions, including the visible-light assisted infrared photodetection technology, the vertical nanowire array technology, and band engineering by the growth of InAsSb nanowires with increasing Sb components, are elaborated to obtain longer cut-off wavelength coverage of photodetectors. Finally, the potentials and challenges of the state-of-the-art optoelectronic technologies for InAs nanowire MWIR photodetectors are summarized and compared, and preliminary suggestions for the technical development route and prospects are presented. This review mainly delineates the research progress of material growth, device fabrication and performance characterization of InAs nanowire MWIR photodetectors, providing a reference for the development of the next-generation high-performance photodetectors over a wide spectrum range.
关键词： nanowire,vertical array,InAsSb,mid-wave infrared photodetector,InAs
更新于2025-09-19 17:13:59
-
[IEEE 2019 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon (EUROSOI-ULIS) - Grenoble, France (2019.4.1-2019.4.3)] 2019 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon (EUROSOI-ULIS) - Nanowire & Nanosheet FETs for Ultra-Scaled, High-Density Logic and Memory Applications
摘要： We report on vertically stacked lateral nanowires (NW)/nanosheets (NS) gate-all-around (GAA) FET devices as promising candidates to obtain a better power-performance metric for logic applications for advanced sub-5nm technology nodes, in comparison to finFETs. In addition, vertical NW/NS GAA FETs appear particularly attractive for enabling highly dense memory cells such as SRAMs (with improved read and write stability), and as the selector devices for ultra-scaled MRAMs with lower energy consumption values. These cells can be manufactured by a cost-effective, co-integration scheme with a finFET or NW/NS FET high-performance logic platform for increased on-chip memory content.
关键词： lateral and vertical nanowire and nanosheet gate-all-around FETs,memory,CMOS,logic,scaling,MRAM
更新于2025-09-19 17:13:59
-
Flexible perovskite solar cells based on AgNW/ATO composite transparent electrodes
摘要： Silver nanowire (AgNW) transparent electrodes are promising for ?exible perovskite solar cells (PSCs) due to their low cost, high conductivity, high transmittance and roll-to-roll fabrication processes. We resolved problems with incorporating AgNW networks into PSCs such as smooth surface morphology, space ?lling and chemical stability by employing solution-deposition of conductive ATO nanoparticles onto pre-existing AgNW networks at low temperatures. AgNW/ATO composite transparent electrodes show a transmission of 76–82 % in the visible region with an excellent sheet resistance of 18 O sq?1, similar to the commercial PET/ITO transparent electrodes. To build up ?exible PSCs, we adopted an architecture in which the thin ?lm of CH3NH3PbI3 was sandwiched between the ZnO (as the electron-selective layer) and carbon electrode (as the hole-selective layer) on the AgNW/ATO composite transparent electrodes. Under AM 1.5 G and 100 mW cm?2 simulated sunlight illumination, the ?exible PSCs based on AgNW/ATO composite transparent electrodes achieved PCEs of 5.07 %. The ?exible devices maintained their performance after 100 bending cycles at 6 mm radius of curvature.
关键词： Transparent electrode,Silver nanowire,ATO nanoparticles,Flexible,Perovskite solar cell
更新于2025-09-19 17:13:59
-
Evidence of Low Temperature Joints in Silver Nanowire Based Transparent Conducting Layers for Solar cells
摘要： The primary stage of joint formation of silver nanowires (AgNWs) at 60 °C is investigated using rotary scanning transmission electron microscopy (STEM with tomographic reconstruction images), and super large-scale molecular dynamic (MD) simulation (2×106 atoms). This study proves to establish that silver nanowires do not require the conventional high temperature post treatment process at 200 °C to form fused contacts at the intersections. In fact, a low temperature annealing at 60 °C facilitates formation of highly conductive networks. The connection between the nanowires is made through a stage called thinning, shown in this report for the first time, which occurs before broadening of the nanowires and is caused due to simultaneous effects of loads from the top nanowires and the heating, as confirmed by STEM and MD result. The outcomes of our investigation significantly promote the application of AgNWs as a transparent conductive layer for solar cells with requirement of low temperature processing such as Kasterite, Perovskite and Organic solar cells.
关键词： Low temperature process,Scanning transmission electron microscopy,Molecular dynamic simulation,Junction resistivity,Transparent conductive layer,Silver nanowire
更新于2025-09-19 17:13:59
-
Energy-Level Graded Al-doped ZnO Protection Layer for Copper Nanowire-Based Window Electrodes for Efficient Flexible Perovskite Solar Cells
摘要： Flexible perovskite solar cells (PSCs) have attracted significant interest as promising candidates for portable and wearable devices. Copper nanowires (CuNWs) are promising candidates for transparent conductive electrodes for flexible PSCs because of their excellent conductivity, flexibility, and cost-effectiveness. However, because of the thermal/chemical instability of CuNWs, they require a protective layer for application in PSCs. Previous PSCs with CuNW-based electrodes generally exhibited poor performances compared with their indium tin oxide (ITO)-based counterparts due to the neglect of the interfacial energetics between electron transport layer (ETL) and CuNWs. Herein, an Al-doped ZnO (AZO) protective layer fabricated using atomic layer deposition (ALD) is introduced. The AZO/CuNW-based composite electrode exhibits improved thermal/chemical stability and favorable band alignment between the ETL and CuNWs, based on the Al dopant concentration tuning. As a result, the Al content gradient AZO (g-AZO), composed of three successively deposited AZO layers, leads to highly efficient flexible PSCs with a power conversion efficiency (PCE) of 14.18%, whereas the PCE of PSCs with non-gradient AZO layer is 12.34%. This improvement can be attributed to the efficient electron extraction and reduced charge recombination. Furthermore, flexible PSCs based on g-AZO-based composite electrodes retain their initial PCE, even after 600 bending cycles, demonstrating excellent mechanical stability.
关键词： copper nanowire,flexible perovskite solar cell,transparent bottom electrode,energy level alignment,atomic layer deposition
更新于2025-09-19 17:13:59
-
Facile Fabrication of Highly Conductive, Ultra-Smooth and Flexible Silver Nanowire Electrode for Organic Optoelectronic Devices
摘要： So far, one of the fundamental limitations of silver nanowires is the high contact resistance among their junctions. Moreover, a rough surface due to its random arrangement is inevitable to electrical short when the nanowire-based electronics is driving. To improve the contact resistance, we suggest the particle-shape nanocrystals are intentionally reduced at the junctions by a localized Joule-heat reduction approach from the silver ions. Via localized reductions, the reduced nanoparticles effectively weld the junction’s areas resulting in a 19% decrease in sheet resistance to 9.9 ?sq-1. Besides, the nanowires are embedded into a polyamide film with a gentle hot pressing. Consequently, the roughness was considerably dropped so that it was successful to demonstrate OLEDs (organic light-emitting diodes) with nanowires, which was beneficial to be laminated with OLEDs under the low temperature. The experimental results show the Ag NW embedding films reach 10.9?sq-1 of the sheet resistance at 92% transmittance and the roughness was only 1.92nm.
关键词： embedding,transferring,joule-heat reduction,smooth surface,silver nanowire,transparent conductive electrode
更新于2025-09-19 17:13:59
-
Miniaturized GaAs Nanowire Laser with a Metal Grating Reflector
摘要： This work proposed a miniaturized nanowire laser with high end-facet re?ection. The high end-facet re?ection was realized by integrating an Ag grating between the nanowire and the substrate. Its propagation and re?ection properties were calculated using the ?nite elements method. The simulation results show that the re?ectivity can be as high as 77.6% for a nanowire diameter of 200 nm and a period of 20, which is nearly three times larger than that of the nanowire without a metal grating re?ector. For an equal length of nanowire with/without the metal grating re?ector, the corresponding threshold gain is approximately a quarter of that of the nanowire without the metal grating re?ector. Owing to the high re?ection, the length of the nanowire can be reduced to 0.9 μm for the period of 5, resulting in a genuine nanolaser, composed of nanowire, with three dimensions smaller than 1 μm (the diameter is 200 nm). The proposed nanowire laser with a lowered threshold and reduced dimensions would be of great signi?cance in on-chip information systems and networks.
关键词： nanowire,nanolaser,metal grating
更新于2025-09-19 17:13:59