- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Enhanced stability and performance of poly(4-vinylpyridine) modified perovskite solar cell with quaternary semiconductor Cu2MSnS4 (M= Co2+, Ni2+, Zn2+) as hole transport materials
摘要： In this work, highly stable and efficient perovskite solar cells (PSCs) in n-i-p configuration has been fabricated. Application of poly (4-vinylpyridine) (PVP) interlayer into the perovskite films via solution based process and quaternary semiconductor Cu2MSnS4 (M = Co2+, Ni2+, Zn2+) (CMTS) nanostructure particles as an inorganic hole transporting material (HTM), result in modified perovskite surface and improving the long term stability and the photovoltaic parameters of the PSCs. The power conversion efficiency (PCE) of the record device with Cu2ZnSnS4(CZTS) HTM and PVP interlayer reaches 13.57%, Voc gains 1.03 V, fill factor (FF) increases up to 70.64% and the device demonstrates low hysteresis (4.14%). Photoluminescence (PL), absorption spectra, electrochemical impedance spectroscopy (EIS) and FESEM images reveal that, the interface between PVP and inorganic CMTS nanostructure particles favorably can reduce non-radiative recombination and enhance Voc. In addition, the presence of hydrophobic PVP interlayer and CMTS nanostructure particles capping with PVP ligands prevent the ingress of the moisture in to the perovskite layer and result in improved stability, where the devices based on CZTS HTM, retain 97% of the initial efficiency after 30 days at room temperature and 35–40% relative humidity.
关键词： Poly(4-vinylpyridine) (PVP),Stability,Quaternary semiconductor,Perovskite solar cell
更新于2025-09-19 17:13:59
-
Comparison of photoselective green light laser vaporisation versus traditional transurethral resection for benign prostate hyperplasia: an updated systematic review and meta-analysis of randomised controlled trials and prospective studies
摘要： Objective To assess the efficacy and safety of green-light laser photoselective vaporisation of the prostate (PVP) compared with transurethral resection of the prostate (TURP) for lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). Design Systematic review and meta-analysis, conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. Data sources PubMed, EMBASE, the Cochrane Library until October 2018. Eligibility criteria Randomised controlled trials and prospective studies comparing the safety and efficacy of PVP versus TURP for LUTS manifesting through BPH. Data extraction and synthesis Perioperative parameters, complications rates and functional outcomes including treatment-related adverse events such as International Prostate Symptom Score (IPSS), maximum flow rate (Qmax), postvoid residual (PVR), quality of life (QoL) and International Index of Erectile Function (IIEF). results 22 publications consisting of 2665 patients were analysed. Pooled analysis revealed PVP is associated with reduced blood loss, transfusion, clot retention, TUR syndrome, capsular perforation, catheterisation time and hospitalisation, but also with a higher reintervention rate and longer intervention duration (all p<0.05). No significant difference in IPSS, Qmax, QoL, PVR or IIEF at 3, 24, 36 or 60 months was identified. There was a significant difference in QoL at 6 months (MD=?0.08; 95% CI ?0.13 to ?0.02; p=0.007), and IPSS (MD = ?0.10; 95% CI ?0.15 to ?0.05; p<0.0001) and Qmax (MD=0.62; 95% CI 0.06 to 1.19; p=0.03) at 12 months, although these differences were not clinically relevant. Conclusion PVP is an effective alternative, holding additional safety benefits. PVP has equivalent long-term IPSS, Qmax, QoL, PVR, IIEF efficacy and fewer complications. The main drawbacks are dysuria and reintervention, although both can be managed with non-invasive techniques. The additional shortcoming is that PVP does not acquire histological tissue examination which removes an opportunity to identify prostate cancer.
关键词： PVP,transurethral resection of the prostate,benign prostatic hyperplasia,photoselective vaporization of the prostate,BPH,green-light laser,vaporization,TURP
更新于2025-09-19 17:13:59
-
Improved photoelectric performance of all-inorganic perovskite through different additives for green light-emitting diodes
摘要： The exceptional optical and electronic properties of all-inorganic cesium lead bromide (CsPbBr3) perovskite make it an ideal new optoelectronic material, but low surface coverage limits its performance. The morphological characteristics of thin films have a great influence on the performance of perovskite light emitting diodes, especially at low coverage, and an inhomogeneous surface will lead to current leakage. To tackle this problem, the widespread adoption of composite layers including polymers poly(ethylene oxide) (PEO) and organic insulating poly(vinylpyrrolidone) (PVP) and all-inorganic perovskites is an effective way to increase the surface coverage and uniformity of perovskite films and improve the performance of perovskite light emitting devices. In our work, the perovskite thin films are investigated by using PEO and PVP dual additives, and the optimized CsPbBr3–PEO–PVP LED with maximum luminance, current efficiency, and external quantum efficiency of 2353 cd m?2 (at 7.2 V), 2.14 cd A?1 (at 6.5 V) and 0.85% (at 6.5 V) was obtained. This work indicates that the method of using additives is not only the key to enhancing the quality of perovskite thin film, but also the key to achieving a higher performance perovskite LED.
关键词： PVP,all-inorganic perovskite,PEO,photoelectric performance,light-emitting diodes
更新于2025-09-16 10:30:52
-
PVP-assisted laser ablation growth of Ag nanocubes anchored on reduced graphene oxide (rGO) for efficient photocatalytic CO2 reduction
摘要： Metallic nanoparticles loaded graphene nanocomposites have been widely studied for various scienti?c and technological applications. In this study, a facile method was reported to realize a straightforward growth of shape and size-controllable of metallic nanoparticles, and the subsequent hybridization with graphene in solution by strategically coupling wet-chemical route and laser ablation. By mixing graphene oxide (GO) with a tunable concentration level of polyvinylpyrrolidone (PVP) in aqueous solution, Ag nanocubes with a face-centered cubic crystal structure were generated by pulsed laser ablation and then mounted on GO nanosheets with the assistance of PVP. The preferential adsorption of PVP to Ag (100) crystal face led to the production of Ag nanocubes with exposed (100) facet. The result showed that the morphological yield of spherical particles decreased with the increase in PVP concentration. X-ray di?raction (XRD) and UV–visible spectroscopy analyses con?rmed that GO was partially reduced. In the reduction of CO2 gas, the photocatalytic conversion rate could achieve 133.1 μmol g?1 in 6 hrs for cubic Ag-loaded reduced GO composites.
关键词： Ag nanocubes,PVP,Laser ablation,CO2 reduction,Photocatalysis,Graphene oxide
更新于2025-09-12 10:27:22
-
Effect of PVP-Capped ZnO Nanoparticles with Enhanced Charge Transport on the Performance of P3HT/PCBM Polymer Solar Cells
摘要： We attempted surface modification in ZnO nanoparticles (NPs) synthesized by the sol–gel process with polyvinyl pyrrolidone (PVP) applied to bulk-heterojunction polymer solar cells (PSCs) as an electron transport layer (ETL). In general, ZnO NPs have trap sites due to oxygen vacancies which capture electrons and degrade the performance of the PSCs. Devices with six different PVP:Zn ratios (0.615 g, 1.230 g, 1.846 g, 2.460 g, 3.075 g, and 3.690 g) were fabricated for surface modification, and the optimized PVP:Zn ratio (2.460 g) was found for PSCs based on P3HT/PCBM. The power conversion efficiency (PCE) of the fabricated PSCs with PVP-capped ZnO exhibited a significant increase of approximately 21% in PCE and excellent air-stability as compared with the uncapped ZnO-based PSCs.
关键词： ZnO,polymer solar cells,PVP,surface modulation,oxygen,bulk-heterojunction,polyvinyl pyrrolidone
更新于2025-09-12 10:27:22
-
Optimization and performance of nitrogen-doped carbon dots as a color conversion layer for white-LED applications
摘要： In this study, green-emitting nitrogen-doped carbon dots (N-CDots) were synthesized and incorporated into drop-cast composite films for use as color conversion layers in a white-LED configuration to generate white light. In order to resolve the red deficiency of this configuration, a commercial red phosphor was integrated into the system. Moreover, the N-CDots were also processed into polymer/N-CDot composite fibers, for which we determined the amount of N-CDots that yielded adequate white-light properties. Finally, we showed that white light with excellent properties could be generated by employing both of the fabricated N-CDot composites either as drop-cast films or composite fibers. Hence, N-CDots provide a promising alternative to inorganic phosphors that are commonly employed in white-LED configurations.
关键词： PVP,nitrogen-doped carbon dots,color conversion layer,electrospinning,white-light generation,white LED,solid-state lighting
更新于2025-09-11 14:15:04
-
Luminescence Properties of Co-doped Eu3+, Bi3+ Lu2O3/Polyvinylpyrrolidone Films
摘要： The effect of the polyvinylpyrrolidone (PVP, MW = 130,000) molar content, PVP/Lu = 1, 2.5, 4 and 5; on the photoluminescent and structural properties of sol-gel derived Lu2O3:Eu3+, Bi3+ has been analyzed. Thin hybrid films were deposited by means of the dip-coating technique on silica quartz substrates. Films deposited at 700 ?C presented a cubic structure, with non-preferential orientation, even with the presence of PVP. The photoluminescence (PL) spectrum and Comission Internationale de l’éclairage (CIE) chromaticity diagram of films revealed a reddish Eu3+ emission at 612 nm (5D0 → 7F2) with an excitation at 320 nm of the Bi ions (6s2 → 6s6p), showing a highly-effective energy transfer process form Bi3+ to Eu3+ luminescent centers. On the other hand, the color temperature of the samples is strongly dependent on the PVP content, as a consequence of the observed difference on the branching ratios of 5D0 → 7FJ transitions of europium ions. Lifetime studies present two different behaviors for the thin films: A non-exponential nature for the lower PVP contents, and a simple exponential nature for the highest PVP one, showing that the PVP tends to promote a better dissolution of segregates and, therefore, increases the lifetime of the Eu3+ emission.
关键词： co-doped Eu3+, Bi3+,photoluminescence,polyvinylpyrrolidone (PVP),Lu2O3
更新于2025-09-09 09:28:46
-
Solution-processed flexible non-volatile resistive switching device based on poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4, 8-diyl)]: polyvinylpyrrolidone composite and its conduction mechanism
摘要： Recently, solution-processed resistive switches for wearable electronics have got tremendous attention and are required for different applications due to their easy process and fabrication. Hence, this paper proposes the solution-processed resistive switching memory device based on two polymers, poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4, 8-diyl)] (F8BT) and polyvinylpyrrolidone (PVP) composite, which is fabricated on a flexible indium–tin–oxide (ITO)-coated polyethylene terephthalate (PET) substrate through spin coating technology. The fabricated device demonstrates a perfect non-volatile bipolar resistive switching through small operating voltage sweeping of ± 1.5 V, and its high-resistance state (HRS) and low-resistance state (LRS) are 92678.89 ? and 337.85 ?, respectively. To verify the non-volatility and long-term stability, the device is checked for more than 700 endurance cycles. During these cycles, the variations of HRS and LRS are 48 ? and 37.35 ?, respectively. The retention time is checked for more than 60 days, and the ROFF/RON ratio is 274.31. The bendability is carried out up to bending diameters < 10 mm, and FESEM is used for the morphological characteristics of the device. Conduction mechanism of the proposed device is supported by space charge-limited conduction (SCLC) which is explained by the log–log I–V slope-fitting curve. The results insure that the F8BT:PVP composite-based resistive switching device is to be a potential candidate for the future flexible and low-power non-volatile resistive switching memory device.
关键词： Resistive switching,Composite,F8BT,Solution-processed,Flexible,Non-volatile,PVP,Conduction mechanism
更新于2025-09-04 15:30:14