scholarly journals Perovskite superlattices with efficient carrier dynamics

2021 ◽  
Author(s):  
Sheng Xu ◽  
Yusheng Lei ◽  
Yuheng Li ◽  
Chengchangfeng Lu ◽  
Qizhang Yan ◽  
...  
Keyword(s):  
Quantum Confinement ◽  
Carrier Transport ◽  
Relaxation Mechanism ◽  
Open Circuit ◽  
Carrier Dynamics ◽  
Metal Halide ◽  
Three Dimensions ◽  
Electrical Performance ◽  
Thickness Direction ◽  
Low Dimensional

Abstract Compared with their three-dimensional counterparts, low-dimensional metal halide perovskites with periodic inorganic/organic structures have shown promising stability and hysteresis-free electrical performance, which paves the way for next-generation optoelectronic devices. However, when integrated in devices, they have relatively limited efficiencies because devices usually require carrier transport through the film thickness direction. In conventionally grown single crystals, the carrier transport in the thickness direction is hindered by the insulating organic spacers. In addition, the strong quantum confinement from the organic spacers limits the generation and transport of free carriers. The carrier dynamics is further compromised by the presence of grain boundaries in polycrystals. Here, we report a low-dimensional metal halide perovskite superlattice with efficient carrier transport in three dimensions by epitaxial growth. Epitaxy on a slightly lattice-mismatched substrate compresses the organic spacers in the superlattice, which weakens the quantum confinement and further improves carrier dynamics. The performance of a low-dimensional perovskite superlattice solar cell has been certified under the quasi-steady state for the first time. Moreover, the device shows an unusually high open-circuit voltage, due to a unique intra-band exciton relaxation mechanism.

scholarly journals Low dimensional metal halide perovskites and hybrids

2019 ◽  
Vol 137 ◽  
pp. 38-65 ◽  
Author(s):  
Chenkun Zhou ◽  
Haoran Lin ◽  
Qingquan He ◽  
Liangjin Xu ◽  
Michael Worku ◽  
...  
Keyword(s):  
Metal Halide ◽  
Halide Perovskites ◽  
Low Dimensional

scholarly journals Development and Piezoelectric Properties of a Stack Units-Based Piezoelectric Device for Roadway Application

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7708
Author(s):  
Chenchen Li ◽  
Fan Yang ◽  
Pengfei Liu ◽  
Chaoliang Fu ◽  
Quan Liu ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Piezoelectric Properties ◽  
Maximum Output Power ◽  
Negative Relationship ◽  
High Energy ◽  
Open Circuit ◽  
Load Test ◽  
Electrical Performance ◽  
Maximum Output ◽  
Piezoelectric Device

To improve the energy harvesting efficiency of the piezoelectric device, a stack units-based structure was developed and verified. Factors such as stress distribution, load resistance, loads, and loading times influencing the piezoelectric properties were investigated using theoretical analysis and experimental tests. The results show that the unit number has a negative relationship with the generated energy and the stress distribution has no influence on the power generation of the piezoelectric unit array. However, with a small stress difference, units in a parallel connection can obtain high energy conversion efficiency. Additionally, loaded with the matched impedance of 275.0 kΩ at 10.0 kN and 10.0 Hz, the proposed device reached a maximum output power of 84.3 mW, which is enough to supply the low-power sensors. Moreover, the indoor load test illustrates that the electrical performance of the piezoelectric device was positively correlated with the simulated loads when loaded with matched resistance. Furthermore, the electrical property remained stable after the fatigue test of 100,000 cyclic loads. Subsequently, the field study confirmed that the developed piezoelectric device had novel piezoelectric properties with an open-circuit voltage of 190 V under an actual tire load, and the traffic parameters can be extracted from the voltage waveform.

The structure, and electronic and magnetic properties of MX (M=GA, IN; X=S, SE, TE) nanoribbons

2020 ◽  
Vol 34 (18) ◽  
pp. 2050168
Author(s):  
Fei Feng ◽  
Fengdong Lv ◽  
Gongping Zheng ◽  
Guangtao Wang
Keyword(s):  
Magnetic Properties ◽  
Quantum Confinement ◽  
Density Functional ◽  
Quantum Confinement Effect ◽  
Ring Structure ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Semiconductor Behavior ◽  
Low Dimensional ◽  
Edge Side

We used the first principle of density functional theory to perform detailed calculations regarding the structure, and the electronic and magnetic properties of MX (M[Formula: see text]=[Formula: see text]Ga, In; X[Formula: see text]=[Formula: see text]S, Se, Te) nanoribbons. The armchair nanoribbons (ARNs) are nonmagnetic semiconductors, which have even or odd oscillations of bandgaps. All small-sized zigzag nanoribbons (ZRNs) were found to break the six-membered ring structure and move to the center, thereby exhibiting nonmagnetic semiconductor behavior owing to the quantum confinement effect. However, among the large ZRNs, which are all metals, MTe ZRNs are nonmagnetic; this differs from the case of graphene, MoS2 and Ti2CO2 nanoribbons. MX (M[Formula: see text]=[Formula: see text]Ga, In; X[Formula: see text]=[Formula: see text]S, Se) ZRNs exhibited ferromagnetism owing to the presence of the unpaired electrons on the metal-edge side and the magnetic moment of each pair of molecules, which was controlled by the size of the nanoribbons. The results provided a theoretical reference that can be used in the future to produce MX materials for application in low-dimensional semiconductor devices, spin electron transport devices and new magnetoresistance devices.

scholarly journals Electrical Double Percolation of Polybutadiene/Polyethylene Glycol Blends Loaded with Conducting Polymer Nanofibers

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2658
Author(s):  
Jun Morita ◽  
Takanori Goto ◽  
Shinji Kanehashi ◽  
Takeshi Shimomura
Keyword(s):  
Polyethylene Glycol ◽  
Critical Exponent ◽  
Percolation Threshold ◽  
Field Effect ◽  
Carrier Transport ◽  
Three Dimensional ◽  
Scanning Force Microscopy ◽  
Three Dimensions ◽  
Dimensional Variable ◽  
Double Percolation

The critical phenomena of double percolation on polybutadiene (PB)/polyethylene glycol (PEG) blends loaded with poly-3-hexylthiophene (P3HT) nanofibers is investigated. P3HT nanofibers are selectively localized in the PB phase of the PB/PEG blend, as observed by scanning force microscopy (SFM). Moreover, double percolation is observed, i.e., the percolation of the PB phase in PB/PEG blends and that of the P3HT nanofibers in the PB phase. The percolation threshold (φcI) and critical exponent (tI) of the percolation of the PB phase in PB/PEG blends are estimated to be 0.57 and 1.3, respectively, indicating that the percolation exhibits two-dimensional properties. For the percolation of P3HT nanofibers in the PB phase, the percolation threshold (φcII) and critical exponent (tII) are estimated to be 0.02 and 1.7, respectively. In this case, the percolation exhibits properties in between two and three dimensions. In addition, we investigated the dimensionality with respect to the carrier transport in the P3HT nanofiber network. From the temperature dependence of the field-effect mobility estimated by field-effect transistor (FET) measurements, the carrier transport was explained by a three-dimensional variable range hopping (VRH) model.

scholarly journals Synchronous organics removal and copper reduction in semiconductor wastewater with energy recuperation via photocatalytic fuel cell

2020 ◽  
Vol 167 ◽  
pp. 01002
Author(s):  
Sze-Mun Lam ◽  
Man-Kit Choong ◽  
Jin-Chung Sin ◽  
Honghu Zeng
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Electrical Performance ◽  
Electricity Production ◽  
Catalyst Loading ◽  
Carbon Cloth ◽  
Optimal Test ◽  
Energy Recuperation

An effective PFC constructed from ZnO/Zn photoanode and carbon cloth cathode has been proposed to oxidatively degrade organics and reductively treat Cu (II) in the semiconductor wastewater accompanied with electricity production. The cell electrical performance with open circuit voltage of 835 V, maximum power density of 0.003623 mW cm-2 and short circuit current density of 0.0506 mA cm-2 can be obtained using optimized catalyst loading of 1.0 g L-1 and semiconductor wastewater concentration of 10 mg L-1. Under the optimal test, more photogenerated electrons will be facilitated for charge carrier separation in the photoanode, accelerating the organics degradation on anode, and subsequently the electron migrating to cathode for Cu (II) reduction. A complete mineralization with 10 mg L-1 COD and more than 70% Cu (II) removal efficiency can be attained within 180 min. A good reproducibility test has been also witnessed because of the stable photoanode and cathode materials. This work may pave an effective and sustainable approach to concurrently eliminate two kinds of contaminants with energy recuperation in a single chamber.

scholarly journals Investigation of Electrochemical, Thermal and Electrical Performance of 3D Lithium-Ion Battery Module in a High -Temperature Environment

2020 ◽  
Vol 9 (2) ◽  
pp. 151-157
Author(s):  
Snigdha Sharma ◽  
Amrish Kumar Panwar ◽  
Madan Mohan Tripathi
Keyword(s):  
Thermal Properties ◽  
Lithium Ion Battery ◽  
Simulation Study ◽  
Lithium Ion ◽  
Open Circuit ◽  
Electrical Performance ◽  
Li Ion Battery ◽  
Peak Voltage ◽  
Simulation And Optimization ◽  
Li Ion

In the present time, the rechargeable lithium-ion battery is being commercialized to meet the sustained market’s demands. To design a more reliable, safe, and efficient Li-ion battery, a 3-D simulation study has been presented in this paper. In this study, a lithium-ion coin-cell is proposed which has LiFePO4 as a positive electrode with a thickness of 1.76 µm, carbon as a negative electrode with a thickness of 2.50 µm and Celgard 2400 polypropylene sheet as a separator between the electrodes with a thickness of 2 µm. The proposed Li-ion battery has been designed, analyzed, and optimized with the help of Multiphysics software. The simulation study has been performed to analyze the electrochemical properties such as cyclic voltammetry (CV) and impedance spectroscopy (EIS). Moreover, the electrical and thermal properties at the microscopic level are investigated and optimized in terms of surface potential distribution, the concentration of electrolyte, open circuit, and surface temperature with respect to time. It has been noticed that the peak voltage, 3.45 V is observed as the temperature distribution on the surface varies from 0 OC to 80 OC at a microscopic scale with different C-rates. The analysis of simulation results indicates a smoother electrode surface with uniform electrical and thermal properties distribution resulting in improved reliability of the battery. The performed simulation and optimization are helpful to achieve control over battery performance and safe usage without any degradation of the environment.©2020. CBIORE-IJRED. All rights reserved.

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