A high-performance cupric oxide photocatalyst with palladium light trapping nanostructures and a hole transporting layer for photoelectrochemical hydrogen evolution

2019 ◽  
Vol 7 (39) ◽  
pp. 22332-22345 ◽  
Author(s):  
Saeid Masudy-Panah ◽  
Reza Katal ◽  
Negar Dasineh Khiavi ◽  
Ehsan Shekarian ◽  
Jiangyong Hu ◽  
...  
Keyword(s):  
High Performance ◽  
Collection Efficiency ◽  
Cupric Oxide ◽  
Light Trapping ◽  
Photogenerated Electron ◽  
Limiting Factors ◽  
Electron Hole ◽  
Absorption Length ◽  
Charge Collection Efficiency ◽  
Hole Transporting

The high recombination rate of photogenerated electron–hole pairs, poor photocorrosion stability, and the discrepancy between the optical absorption length and charge collection efficiency of cupric oxide (CuO) are the main limiting factors of CuO photocatalysts.

scholarly journals Perspective on Predominant Metal Oxide Charge Transporting Materials for High-Performance Perovskite Solar Cells

2021 ◽  
Vol 8 ◽  
Author(s):  
Mriganka Singh ◽  
Chih Wei Chu ◽  
Annie Ng
Keyword(s):  
Solar Cells ◽  
Metal Oxide ◽  
Charge Transport ◽  
High Performance ◽  
Collection Efficiency ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Future Research ◽  
Charge Collection Efficiency ◽  
Oxide Charge

Nowadays, the power conversion efficiency of organometallic mixed halide perovskite solar cells (PSCs) is beyond 25%. To fabricate highly efficient and stable PSCs, the performance of metal oxide charge transport layers (CTLs) is one of the key factors. The CTLs are employed in PSCs to separate the electrons and holes generated in the perovskite active layer, suppressing the charge recombination rate so that the charge collection efficiency can be increased at their respective electrodes. In general, engineering of metal oxide electron transport layers (ETLs) is found to be dominated in the research community to boost the performance of PSCs due to the resilient features of ETLs such as excellent electronic properties, high resistance to thermal temperature and moisture, ensuring good device stability as well as their high versatility in material preparation. The metal oxide hole transport layers in PSCs are recently intensively studied. The performance of PSCs is found to be very promising by using optimized hole transport materials. This review concisely discusses the evolution of some prevalent metal oxide charge transport materials (CTMs) including TiO2, SnO2, and NiOx, which are able to yield high-performance PSCs. The article begins with introducing the development trend of PSCs using different types of CTLs, pointing out the important criteria for metal oxides being effective CTLs, and then a variety of preparation methods for CTLs as employed by the community for high-performance PSCs are discussed. Finally, the challenges and prospects for future research direction toward scalable metal oxide CTM-based PSCs are delineated.

scholarly journals Synthesis and characterization of Z-scheme heterostructure CoWO4/g-C3N4 as a visible-light photocatalyst for removal of organic pollutant

2021 ◽  
Vol 10 (2) ◽  
pp. 59-63
Author(s):  
Hai Pham Viet ◽  
Anh Dao Thi Ngoc ◽  
Viet Nguyen Minh ◽  
Ha Tran Thi Viet ◽  
Dang Do Van ◽  
...  
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
High Performance ◽  
Organic Pollutant ◽  
Photogenerated Electron ◽  
Morphological Properties ◽  
Electron Hole ◽  
Visible Light Photocatalyst ◽  
Photocatalytic Activities

In this study, direct Z–scheme heterostructure CoWO4/g-C3N4 was synthesized by a facile hydrothermal method. The structural, morphological properties of the prepared samples were characterised by XRD, SEM, UV–Vis and PL measurements. The as-obtained heterostructure CoWO4/g-C3N4 exhibited enhanced photocatalytic activities toward the degradation of Rhodamine B under visible light irradiation with 92% Rhodamine B removal after 80 minutes irritation, which exceeded pristine g-C3N4 and CoWO4. The enhanced photocatalytic performance ascribed to interfacial contact between g-C3N4 and CoWO4, thus further inhibiting the recombination of photogenerated electron/hole pairs. It is anticipated that the construction of Z–scheme heterostructure CoWO4/g-C3N4 is an effective strategy to develop high-performance photocatalysts for the degradation of organic pollutants in water.

Silicon Carbide for Alpha, Beta, Ion and Soft X-Ray High Performance Detectors

2005 ◽  
Vol 483-485 ◽  
pp. 1015-1020 ◽  
Author(s):  
Giuseppe Bertuccio ◽  
Simona Binetti ◽  
S. Caccia ◽  
R. Casiraghi ◽  
Antonio Castaldini ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Collection Efficiency ◽  
High Energy ◽  
Beta Particle ◽  
High Energy Resolution ◽  
Charge Collection Efficiency ◽  
X Ray ◽  
Current Densities ◽  
Full Charge

High performance SiC detectors for ionising radiation have been designed, manufactured and tested. Schottky junctions on low-doped epitaxial 4H-SiC with leakage current densities of few pA/cm2 at room temperature has been realised at this purpose. The epitaxial layer has been characterised at different dose of radiations in order to investigate the SiC radiation hardness. The response of the detectors to alpha and beta particle and to soft X-ray have been measured. High energy resolution and full charge collection efficiency have been successfully demonstrated.

scholarly journals The mini-JPAS: A Study of the Wavelength Dependence of the Photon Response Nonuniformity of the JPAS-Pathfinder Camera

2021 ◽  
Vol 257 (2) ◽  
pp. 31
Author(s):  
Kai Xiao ◽  
Haibo Yuan ◽  
J. Varela ◽  
Hu Zhan ◽  
Jifeng Liu ◽  
...  
Keyword(s):  
Collection Efficiency ◽  
Wavelength Dependence ◽  
Effective Area ◽  
Photon Absorption ◽  
Charge Collection ◽  
Small Scale ◽  
Model Parameters ◽  
Absorption Length ◽  
Charge Collection Efficiency ◽  
Simple Physical Model

Abstract Understanding the origins of small-scale flats of CCDs and their wavelength-dependent variations plays an important role in high-precision photometric, astrometric, and shape measurements of astronomical objects. Based on the unique flat data of 47 narrowband filters provided by JPAS-Pathfinder, we analyze the variations of small-scale flats as a function of wavelength. We find moderate variations (from about 1.0% at 390 nm to 0.3% at 890 nm) of small-scale flats among different filters, increasing toward shorter wavelengths. Small-scale flats of two filters close in central wavelengths are strongly correlated. We then use a simple physical model to reproduce the observed variations to a precision of about ±0.14% by considering the variations of charge collection efficiencies, effective areas, and thicknesses between CCD pixels. We find that the wavelength-dependent variations of the small-scale flats of the JPAS-Pathfinder camera originate from inhomogeneities of the quantum efficiency (particularly charge collection efficiency), as well as the effective area and thickness of CCD pixels. The former dominates the variations in short wavelengths, while the latter two dominate at longer wavelengths. The effects on proper flat-fielding, as well as on photometric/flux calibrations for photometric/slitless spectroscopic surveys, are discussed, particularly in blue filters/wavelengths. We also find that different model parameters are sensitive to flats of different wavelengths, depending on the relations between the electron absorption depth, photon absorption length, and CCD thickness. In order to model the wavelength-dependent variations of small-scale flats, a small number (around 10) of small-scale flats with well-selected wavelengths are sufficient to reconstruct small-scale flats in other wavelengths.

Synthesis of three-dimensional hyperbranched TiO2nanowire arrays with significantly enhanced photoelectrochemical hydrogen production

2015 ◽  
Vol 3 (7) ◽  
pp. 4004-4009 ◽  
Author(s):  
Zhenghui Pan ◽  
Yongcai Qiu ◽  
Jie Yang ◽  
Meinan Liu ◽  
Lisha Zhou ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
High Performance ◽  
Collection Efficiency ◽  
Three Dimensional ◽  
Absorption Efficiency ◽  
Charge Collection ◽  
Diffusion Distance ◽  
Charge Collection Efficiency ◽  
Photoelectrochemical Hydrogen Production ◽  
Pec Water Splitting

The three-dimensional (3D) hierarchical nanostructure is one of the promising candidates for high performance photoelectrochemical (PEC) water splitting electrodes due to the reduced carrier diffusion distance, improved light absorption efficiency and charge collection efficiency.

scholarly journals Unveiling structure-performance relationships from multi-scales in non-fullerene organic photovoltaics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuixing Li ◽  
Lingling Zhan ◽  
Nannan Yao ◽  
Xinxin Xia ◽  
Zeng Chen ◽  
...  
Keyword(s):  
Organic Photovoltaics ◽  
High Performance ◽  
Molecular Design ◽  
Collection Efficiency ◽  
Morphological Characteristics ◽  
Molecular Structures ◽  
Radiative Loss ◽  
Charge Collection Efficiency ◽  
Positive Effects ◽  
Optimal Efficiency

AbstractUnveiling the correlations among molecular structures, morphological characteristics, macroscopic properties and device performances is crucial for developing better photovoltaic materials and achieving higher efficiencies. To achieve this goal, a comprehensive study is performed based on four state-of-the-art non-fullerene acceptors (NFAs), which allows to systematically examine the above-mentioned correlations from different scales. It’s found that extending conjugation of NFA shows positive effects on charge separation promotion and non-radiative loss reduction, while asymmetric terminals can maximize benefits from both terminals. Another molecular optimization is from alkyl chain tuning. The shortened alkyl side chain results in strengthened terminal packing and decreased π-π distance, which contribute high carrier mobility and finally the high charge collection efficiency. With the most-acquired benefits from molecular structure and macroscopic factors, PM6:BTP-S9-based organic photovoltaics (OPVs) exhibit the optimal efficiency of 17.56% (certified: 17.4%) with a high fill factor of 78.44%, representing the best among asymmetric acceptor based OPVs. This work provides insight into the structure-performance relationships, and paves the way toward high-performance OPVs via molecular design.

scholarly journals Enhancing Charge Separation in Conjugated Microporous Polymers for Efficient Photocatalytic Hydrogen Evolution

2021 ◽  
Author(s):  
Zhuangfei Qian ◽  
Yajie Yan ◽  
Ziqi Liang ◽  
Xiaodong Zhuang ◽  
Kai A. I. Zhang
Keyword(s):  
Hydrogen Evolution ◽  
Organic Semiconductor ◽  
Charge Separation ◽  
High Efficiency ◽  
Photogenerated Electron ◽  
Limiting Factors ◽  
Electron Hole ◽  
Photocatalytic Hydrogen Evolution ◽  
Microporous Polymers ◽  
Conjugated Microporous Polymers

The fast recombination of photogenerated electron-hole pairs after charge separation is one of the main limiting factors for achieving high efficiency of organic semiconductor photocatalysts. Herein, we report a conjugated...

Toward High-Performance Electron/Hole-Transporting-Layer-Free, Self-Powered CsPbIBr2 Photodetectors via Interfacial Engineering

2020 ◽  
Vol 12 (5) ◽  
pp. 6607-6614 ◽  
Author(s):  
Zeyulin Zhang ◽  
Wentao Zhang ◽  
Qubo Jiang ◽  
Ziming Wei ◽  
Mingyu Deng ◽  
...  
Keyword(s):  
High Performance ◽  
Electron Hole ◽  
Interfacial Engineering ◽  
Hole Transporting ◽  
Self Powered

Electron beam induced current study of thin silicon layers on insulator substrate

1990 ◽  
Vol 48 (4) ◽  
pp. 618-619
Author(s):  
A. Buczkowski ◽  
Z. J. Radzimski ◽  
J. C. Russ ◽  
G. A. Rozgonyi
Keyword(s):  
Electron Beam ◽  
Energy Loss ◽  
Beam Energy ◽  
Collection Efficiency ◽  
Silicon Layer ◽  
Depletion Layer ◽  
Incident Electron Energy ◽  
Induced Current ◽  
Electron Hole ◽  
Electron Beam Induced Current

If a thickness of a semiconductor is smaller than the penetration depth of the electron beam, e.g. in silicon on insulator (SOI) structures, only a small portion of incident electrons energy , which is lost in a superficial silicon layer separated by the oxide from the substrate, contributes to the electron beam induced current (EBIC). Because the energy loss distribution of primary beam is not uniform and varies with beam energy, it is not straightforward to predict the optimum conditions for using this technique. Moreover, the energy losses in an ohmic or Schottky contact complicate this prediction. None of the existing theories, which are based on an assumption of a point-like region of electron beam generation, can be used satisfactorily on SOI structures. We have used a Monte Carlo technique which provide a simulation of the electron beam interactions with thin multilayer structures. The EBIC current was calculated using a simple one dimensional geometry, i.e. depletion layer separating electron- hole pairs spreads out to infinity in x- and y-direction. A point-type generation function with location being an actual location of an incident electron energy loss event has been assumed. A collection efficiency of electron-hole pairs was assumed to be 100% for carriers generated within the depletion layer, and inversely proportional to the exponential function of depth with the effective diffusion length as a parameter outside this layer. A series of simulations were performed for various thicknesses of superficial silicon layer. The geometries used for simulations were chosen to match the "real" samples used in the experimental part of this work. The theoretical data presented in Fig. 1 show how significandy the gain decreases with a decrease in superficial layer thickness in comparison with bulk material. Moreover, there is an optimum beam energy at which the gain reaches its maximum value for particular silicon thickness.

scholarly journals Construction of Ag3PO4/SnO2 Heterojunction on Carbon Cloth with Enhanced Visible Light Photocatalytic Degradation

2020 ◽  
Vol 10 (9) ◽  
pp. 3238
Author(s):  
Min Liu ◽  
Guangxin Wang ◽  
Panpan Xu ◽  
Yanfeng Zhu ◽  
Wuhui Li
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Carbon Cloth ◽  
Electron Hole ◽  
Step Process ◽  
Photogenerated Electrons ◽  
Rapid Transfer ◽  
Visible Light Photocatalytic

In this study, the Ag3PO4/SnO2 heterojunction on carbon cloth (Ag3PO4/SnO2/CC) was successfully fabricated via a facile two-step process. The results showed that the Ag3PO4/SnO2/CC heterojunction exhibited a remarkable photocatalytic performance for the degradation of Rhodamine B (RhB) and methylene blue (MB), under visible light irradiation. The calculated k values for the degradation of RhB and MB over Ag3PO4/SnO2/CC are 0.04716 min−1 and 0.04916 min−1, which are higher than those calculated for the reactions over Ag3PO4/SnO2, Ag3PO4/CC and SnO2/CC, respectively. The enhanced photocatalytic activity could mainly be attributed to the improved separation efficiency of photogenerated electron-hole pairs, after the formation of the Ag3PO4/SnO2/CC heterojunction. Moreover, carbon cloth with a large specific surface area and excellent conductivity was used as the substrate, which helped to increase the contact area of dye solution with photocatalysts and the rapid transfer of photogenerated electrons. Notably, when compared with the powder catalyst, the catalysts supported on carbon cloth are easier to quickly recycle from the pollutant solution, thereby reducing the probability of recontamination.

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