- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Laser Annealing Enhanced the Photophysical Performance of Pt/n-PSi/ZnO/Pt-Based Photodetectors
摘要： Herein, the effect of pulsed Nd:YAG laser irradiation at different fluencies in air at room temperature on the performance of n-PSi/ZnO-based UV MSM photodetector was demonstrated. Thermal and photon energies were coupled to synthesize n-PSi/ZnO NCs heterojunctions. The porous silicon (PSi) films with nano-sized pore arrays were first prepared via photoelectrochemical etching (PECE) of n-type silicon wafers with 45 mA/cm2 current density for a duration of 30 min. This was followed by radio frequency sputtering (RFS) of ZnO on PSi at 700 oC and irradiating with a Nd: YAG laser pulses with laser fluence of 40 mJ/cm2. X-ray diffraction analysis indicates the formation of ZnO wurtzite hexagonal crystal structure of n-PSi/ZnO NCs, where the crystallite size decreases (96-29 nm) with number of pulses. Field emission electron scanning microscopy and atomic force microscopy reveal porous nanostructure, arrays of nearly spherically shape particles homogeneously distributed on the entire surface where roughness increases (84-139 nm) with number of pulses. Photoluminescence spectroscopy reveals intrinsic band-to-band transition, donor-acceptor pair emission and quenching of the broadband intensity related to improved of crystallinity, meanwhile the band gap energy of the n-PSi/ZnO NCs is found to decrease (3.26 – 3.13 V). The Nd:YAG laser annealing demonstrate a positive effect on the properties of n-PSi/ZnO NCs photodetector, exhibiting very high sensitivity (3772.92) and very short rise and recovery times (0.30 s and 0.26 s).
关键词： Porous silicon,n-PSi/ZnO junction,Nd-YAG laser,photodetectors
更新于2025-09-23 15:19:57
-
Manufacturing and Characterization on aThree-Dimensional Random Resonator of Porous Silicon/TiO <sub/>2</sub> Nanowires for Continuous Light Pumping Lasing of Perovskite Quantum Dots
摘要： In recent years, all inorganic bismuth lead-halide perovskite nanocrystals [CsPbX3 (X ? Cl, Br, I)] have received extensive attention due to their high performance in °uorescence quantum yield, narrow emission spectrum, and adjustable emission range. However, the disadvantages of high cost and poor stability have greatly limited the development prospects of the material. Here, in order to develop a perovskite quantum dot lasing cavity with high chemical stability, high quality factor and low fabrication cost, we have successfully fabricated a 3D random cavity device based on porous silicon/TiO2 nanowires. A TiO2 nanowire is grown on the porous silicon to form a 3D resonant cavity, and a perovskite quantum dot is spin-coated on the surface of the 3D resonant cavity to form a novel 3D complex ˉlm. The novel structure enhances the chemical stability and lasing quality factor of the resonant cavity while the °uorescence generated by the large quantum dots in the spatial interference structure constitutes the feedback loop, which will provide favorable support for the development of information optics.
关键词： porous silicon,Perovskite quantum dots,TiO2,resonators
更新于2025-09-23 15:19:57
-
Stretchable and Skin-Conformable Conductors Based on Polyurethane/Laser-Induced Graphene
摘要： The conversion of various polymer substrates into laser-induced graphene (LIG) with a CO2 laser in ambient condition is recently emerging as a simple method for obtaining patterned porous graphene conductors, with a myriad of applications in sensing, actuation, and energy. In this paper, a method is presented for embedding porous LIG (LIG-P) or LIG fibers (LIG-F) into a thin (about 50 μm) and soft medical grade polyurethane (MPU) providing excellent conformal adhesion on skin, stretchability, and maximum breathability to boost the development of various unperceivable monitoring systems on skin. The effect of varying laser fluence and geometry of the laser scribing on the LIG micro?nanostructure morphology and on the electrical and electromechanical properties of LIG/MPU composites is investigated. A peculiar and distinct behavior is observed for either LIG-P or LIG-F. Excellent stretchability without permanent impairment of conductive properties is revealed up to 100% strain and retained after hundreds of cycles of stretching tests. A distinct piezoresistive behavior, with an average gauge factor of 40, opens the way to various potential strain/pressure sensing applications. A novel method based on laser scribing is then introduced for providing vertical interconnect access (VIA) into LIG/MPU conformable epidermal sensors. Such VIA enables stable connections to an external measurement device, as this represents a typical weakness of many epidermal devices so far. Three examples of minimally invasive LIG/MPU epidermal sensing proof of concepts are presented: as electrodes for electromyographic recording on limb and as piezoresistive sensors for touch and respiration detection on skin. Long-term wearability and functioning up to several days and under repeated stretching tests is demonstrated.
关键词： biosensor,epidermal,porous graphene,stretchable conductor,laser
更新于2025-09-23 15:19:57
-
Oxygen Vacancies Enabled Porous SnO <sub/>2</sub> Thin Films for Highly Sensitive Detection of Triethylamine at Room Temperature
摘要： Detection of volatile organic compounds (VOCs) at room temperature (RT) currently remains a challenge for metal oxide semiconductor (MOS) gas sensors. Herein, we for the first time report on the utilization of porous SnO2 thin films for RT detection of VOCs by defect engineering of oxygen vacancies. The oxygen vacancies in the three-dimensional ordered SnO2 thin films, prepared by a colloidal template method, can be readily manipulated by thermal annealing at different temperatures. It is found that oxygen vacancies play an important role in the RT sensing performances, which successfully enables the sensor to respond to triethylamine (TEA) with an ultrahigh response, e.g. 150.5 to 10 ppm TEA in a highly selective manner. In addition, the sensor based on oxygen vacancy-rich SnO2 thin films delivers a fast response and recovery speed (53 and 120 s), which can be further shortened to 10 and 36 s by elevating the working temperature to 120 oC. Notably, a low detection limit of 110 ppb has been obtained under RT. The overall performances surpass most previous reports on TEA detection at RT. The outstanding sensing properties can be attributed to the porous structure with abundant oxygen vacancies, which can improve the adsorption of molecules. The oxygen vacancy engineering strategy and the on-chip fabrication of porous MOS thin film sensing layers deliver a great potential for create high-performance RT sensors.
关键词： Oxygen vacancy,Porous film,Gas sensor,Tin dioxide,Room temperature
更新于2025-09-23 15:19:57
-
Formation mechanism of porous rose-like WO3 and its photoresponse and stability study
摘要： WO3 materials are widely used in photocatalysis and electrocatalysis. In this work, sodium dodecyl benzene sulfonate (SDBS) was used to control the growth of H2WO4 during chemical bath deposition fabrication process. The as-prepared H2WO4 material showed a rose-like morphology and after annealing the obtained WO3 sample was porous with oxygen defects. XRD, SEM, TEM, XPS and some other method were used to characterize the samples. A possible growth mechanism was given depending on the characterization results. The addition of SDBS resulted in a simultaneous growth of plenty H2WO4 nucleus, which caused a uniform distribution. Compared with normal WO3, the as-fabricated porous rose-like WO3 showed a higher stability to photocorrosion and a narrower band gap.
关键词： porous,photocatalysis,electrocatalysis,oxygen defects,WO3,SDBS
更新于2025-09-23 15:19:57
-
Perovskite Solar Cells: A Porous Graphitic Carbon based Hole Transporter/Counter Electrode Material Extracted from an Invasive Plant Species Eichhornia Crassipes
摘要： perovskite solar cells (pScs) composed of organic polymer-based hole-transporting materials (HtMs) are considered to be an important strategy in improving the device performance, to compete with conventional solar cells. Yet the use of such expensive and unstable HTMs, together with hygroscopic perovskite structure remains a concern – an arguable aspect for the prospect of onsite photovoltaic (PV) application. Herein, we have demonstrated the sustainable fabrication of efficient and air-stable PSCs composed of an invasive plant (Eichhornia crassipes) extracted porous graphitic carbon (ec-Gc) which plays a dual role as HTM/counter electrode. The changes in annealing temperature (~450 °C, ~850 °C and ~1000 °C) while extracting the EC-GC, made a significant impact on the degree of graphitization - a remarkable criterion in determining the device performance. Hence, the fabricated champion device-1c: Glass/fto/c-tio2/mp-tio2/cH3nH3pbi3?xclx/EC-GC10@CH3nH3pbi3?x clx/EC-GC10) exhibited a PCE of 8.52%. Surprisingly, the introduced EC-GC10 encapsulated perovskite interfacial layer at the perovskite/HtM interface helps in overcoming the moisture degradation of the hygroscopic perovskite layer in which the same champion device-1c evinced better air stability retaining its efficiency ~94.40% for 1000 hours. We believe that this present work on invasive plant extracted carbon playing a dual role, together as an interfacial layer may pave the way towards a reliable perovskite photovoltaic device at low-cost.
关键词： Eichhornia crassipes,hole-transporting materials,porous graphitic carbon,perovskite solar cells,device stability
更新于2025-09-23 15:19:57
-
Ultrasensitive and Label-Free Detection of Cell Surface Glycan Using Nanochannel-Ionchannel Hybrid Coupled with Electrochemical Detector
摘要： In this work, asymmetric nanochannel-ionchannel of porous anodic alumina (PAA) coupled with electrochemical detector was used for sensitive and label-free detection of cell surface glycan. The amplified ionic current caused by array nanochannels as well as the ionic current rectification (ICR) caused by asymmetric geometry endows PAA with sensitive ionic current response. Functionalized with the special molecular probe, the constructed nanofluidic device can be used for selective recognition and detection of glycan in real-time and label-free format. In addition, due to the subnanosize of ionchannels, the probe immobilization and glycan recognition is carried out on the outer surface of PAA, avoiding the blockage of PAA nanochannel by samples, which promises the reproducibility and accuracy of the present method toward bioanalysis. Results show that the glycan concentration ranging from 10 fM to 10 nM can be successfully detected with a detection limit of ~10 aM, which is substantially lower than most previous works. The designed strategy provides a valuable platform for sensitive and label-free detection of cell surface glycan, which acts as a promising candidate in pathological research and cancer diagnosis.
关键词： porous anodic alumina,ionic current rectification,cell surface glycan,nanochannel-ionchannel hybrid,nanofluidics
更新于2025-09-23 15:19:57
-
Preparation of triplea??responsive porous silica carriers and carbon quantum dots for photodynamica??chemo therapy and cell multicolor imaging
摘要： Photosensitive carbon quantum dots (CQDs) provide a new route to treat cancer owing to their ability to produce singlet oxygen. In this paper, pH/redox/enzyme-responsive porous silica-based carriers with CQDs were constructed for photodynamic-chemical combination therapy. Porous silica (pSiO2) sample presents uniform sphere with center-radial channels, which is favorable for drug loading and delivery. The CQDs with size of 2.5 nm were synthesized and have the excellent ability to generate singlet oxygen. After loading CQDs and drug molecules, the channels of pSiO2 carrier were blocked with hyaluronic acid (HA)/chitosan (CHI) layer. The disulfide bonds conjugating HA to the surface of pSiO2 carrier would achieve redox-responsive drug release while breaking disulfide bonds and HA/CHI layer could endow the pSiO2 carrier enzyme/pH responsive drug release. The prepared pSiO2 carriers display low cytotoxicity and good biocompatibility for multicolor imaging and photodynamic-chemo therapy.
关键词： CQDs,photodynamic-chemical combination therapy,controlling release,porous silica
更新于2025-09-23 15:19:57
-
Cu2AgInSe4 QDs sensitized electrospun porous TiO2 nanofibers as an efficient photoanode for quantum dot sensitized solar cells
摘要： To obtain an efficient quantum dot sensitized solar cell (QDSC), a less toxic quaternary Cu2AgInSe4 QDs with 4.8 nm in size are synthesized by a simple hot injection method. The crystallite size and tetragonal structure are confirmed by XRD and HR-TEM analysis. Energy-dispersive X-ray spectroscopy analysis reveals that the atomic ratio of Cu: Ag: In: Se in the Cu2AgInSe4 QDs is 1.98:1.0:1.03:3.86. The oxidation state of the elements composed in Cu2AgInSe4 QDs is confirmed by XPS studies. Optical properties are studied from the UV–Vis–NIR absorption spectrum and photoluminescence emission spectrum. The porous TiO2 nanofibers (P-TiO2 NFs) are prepared from the conventional electrospun TiO2 NFs followed by the solvosonication process. The FE-SEM analysis is confirmed the porous texture of the TiO2 NFs. The bandgap of the Cu2AgInSe4 QDs and TiO2 NFs are determined from the Tauc plot and it was found to be 1.93 eV and 3.19 eV, respectively. QDSC is assembled using Cu2S counter electrode, polysulfide redox couple electrolyte and Cu2AgInSe4 QDs sensitized P-TiO2 NFs photoanode. The photoconversion efficiency (PCE) of the assembled QDSC is found to be 4.24%.
关键词： Tauc plot,QDSC,Porous TiO2 Nanofibers,Cu2AgInSe4 QDs,Hot injection method
更新于2025-09-23 15:19:57
-
Xanthene Dye-Functionalized Conjugated Porous Polymers as Robust and Reusable Photocatalysts for Controlled Radical Polymerization
摘要： Photoinduced electron/energy transfer?reversible addition?fragmentation chain transfer (PET?RAFT) polymerization represents a versatile and highly e?cient method for polymerizations of wide-ranging monomer variances upon solar energy harvesting. Although signi?cant progress has been achieved, several drawbacks are still associated with existing photocatalysts, such as toxicity of transition metals, high cost, poor stability, and unavoidable puri?cation procedures because of the photobleaching e?ect, to name a few. Herein, 1,4-diethynylbenzene-linked xanthene dye-conjugated porous polymers (CPPs) have been established as potential heterogenous photocatalysts of PET?RAFT polymerization. With this two-dimensional planar architecture, we demonstrate dual-stimuli toggling of RAFT polymerization using two di?erent external physical manipulations: light “ON”/“OFF” and solution pH “LOW”/“HIGH”. In addition, these CPPs endowed radical polymerizations with various impressive features such as compatibility of diverse monomer formulations, unique oxygen tolerance, and ppm-level catalyst dosage. Demonstrations of chain extension and catalyst recycling further highlight the robustness and performance of this CPP catalyst. Through the study of structure?property relationship using the experimental analyses, we envisage that a series of xanthene dye-functionalized CPPs can be developed as visible light-absorbing organocatalysts rivaling transition-metal photocatalysts.
关键词： PET?RAFT polymerization,visible light-absorbing organocatalysts,xanthene dye-functionalized conjugated porous polymers,dual-stimuli toggling,heterogeneous photocatalysts
更新于2025-09-23 15:19:57