Hybrid polymer/ZnO solar cells sensitized by PbS quantum dots

Poly[2-methoxy-5-(2-ethylhexyloxy-p-phenylenevinylene)]/ZnO nanorod hybrid solar cells consisting of PbS quantum dots [QDs] prepared by a chemical bath deposition method were fabricated. An optimum coating of the QDs on the ZnO nanorods could strongly improve the performance of the solar cells. A maximum power conversion efficiency of 0.42% was achieved for the PbS QDs' sensitive solar cell coated by 4 cycles, which was increased almost five times compared with the solar cell without using PbS QDs. The improved efficiency is attributed to the cascade structure formed by the PbS QD coating, which results in enhanced open-circuit voltage and exciton dissociation efficiency

Surface Dynamics Transition of Vacuum Vapor Deposited CH 3

The growth dynamics of CH3NH3PbI3 perovskite thin films on ITO covered glass substrate were investigated. The evolution of the film could be divided into two stages. A mound-like surface was obvious at the first stage. Stable dynamic scaling was observed for thicker films at the second stage. Through analyzing the scaling exponent, growth exponent β, and 2D fast Fourier transform, it is concluded that, at the second stage, the growth mechanism of mound formation does not play a major role, and the film growth mechanism can be described by Mullins diffusion equation

The Poverty Alleviation Model for Poor Nationalities in the Mountainous Areas of Western China:A Case Study of “Promotion for the Entire Lisu Nationality” in Naimu Danxia Village Group

In poor minority areas, poor living conditions, single industrial structure and weak public basic services often lead to a deep degree of poverty. This is the most difficult problem to solve in the fight against poverty. Yunlong Township, Luquan Yi and Miao Autonomous County, which is located in the alpine canyon area of Jinsha River in China, is a semi-closed agricultural township integrating "nationality, mountain area, poverty and backwardness". Located in the Xinshan Village Committee of this township, Naimu Danxia village group is a typical Lisu settlement. It is a key village group with a deep degree of poverty, and the incidence of poverty is 17.00%. In recent years, Naimu Danxia village group has adhered to the direction of unified promotion, internal and external blood creation and resource integration in the poverty alleviation work of the Lisu nationality in Luquan County. It has successfully taken a road of national unity, self-reliance and common poverty alleviation, and formed a unique poverty alleviation model of "promotion for the entire nationality". At the end of 2018, the incidence of poverty dropped to 0.00%, successfully building a "demonstration village of national unity" at the municipal level in Kunming. Based on the field research and interviews, this paper analyzes and summarizes the specific methods, main achievements, practical experience and popularization and application measures regarding the poverty alleviation model of "promotion for the entire Lisu nationality" in the village group. It tries to provide necessary reference for accurate poverty alleviation and poverty eradication in similar minority areas in Yunnan Province and other provinces

Improved performance of perovskite photodetectors with a hybrid planar-mixed heterojunction

Improved performance of lateral perovskite photodetectors is demonstrated based on a hybrid planar-mixed heterojunction structure, which comprises a CH _3 NH _3 PbI _3 :PC _61 BM ([6,6]-phenyl-C61-butyric acid methyl ester) bulk heterojunction on a planar SnO _2 layer. The photodetector with an optimized PC _61 BM doping concentration shows a photocurrent more than three times to that device without a PC _61 BM doping or without a planar SnO _2 layer, confirming that the hybrid planar-mixed heterojunction structure plays an important role in improving the performance of the devices. The photodetector exhibits a responsivity higher than 2 A W ^−1 in a wide range from ultraviolet to near infrared with a maximum one of 9 A W ^−1 at 315 nm. The improved performance is not only attributed to the increased electron transporting ability and the dissociation probability of excitons and/or electron-hole pairs in perovskite, but also to the growth of compact perovskite films with decreased grain boundary and hence the increased charge carriers transporting efficiency due to the introduction of PC _61 BM

The Influence of Materials, Heterostructure, and Orientation for Nanohybrids on Photocatalytic Activity

Abstract In this work, different structures based on electrodeposited n-type ZnO nanorods and p-type Cu2O, CuSCN, and NiO nanostructures are fabricated for the degradation of methyl orange (MO). The influence of materials, heterostructure, and orientation for nanohybrids on photocatalytic activity is discussed for the first time. The heterojunction structures show remarkable enhancement compared to the bare semiconductor. The morphology of nanostructure has mainly an influence on the photocatalytic activity. NiO has the highest catalytic activity among the four pristine semiconductor nanostructures of ZnO, Cu2O, CuSCN, and NiO. The greatest enhancement of the photocatalytic activity is obtained using a ZnO/NiO (1 min) heterostructure attributed to the heterojunction structure and extremely higher specific surface area, which can degrade MO (20 mg/L) into colorless within 20 min with the fastest photocatalytic speed among homogeneous heterojunction structures. Meanwhile, the methodology and data analysis described herein will serve as an effective approach for the design of hybrid nanostructures for solar energy application, and the appropriate nanohybrids will have significant potential to solve the environment and energy issues

Amorphous-crystalline TiO2/carbon nanofibers composite electrode by one-step electrospinning for symmetric supercapacitor

In this study, the effects of titanium oxycompound templates on carbon nanofibers electrodes for supercapacitors application were investigated. Meanwhile, hybrid titanium that contains organic and inorganic titanium templates acted as another modification method. The organic and inorganic titanium oxycompounds referred to titanium (IV) oxy-acetylacetonate and titanium dioxide nanopowder, respectively. The morphology structure, and electrochemical properties of the three composite electrodes (TiO2@CNFs, OCTi@CNFs, HybTi@CNFs) were studied. Hierarchical pore structure with specific surface area of 697 m(2) g (1) was achieved in HybTi@CNFs, in which TiO2 revealed amorphous, tetragonal rutile and anatase structure. The electron charge transfer resistance and specific capacitance of HybTi@CNFs were calculated to be 0.3412 and 280.3 F g (1) (at current density of 1 A g (1)), respectively. After 4000 cycles with galvanostatic charge/discharge, HybTi@CNFs can maintain 97.5% of its initial capacitance under 8 A g (1) in a symmetric two-electrode system (6M KOH). These results indicate that OCTi@CNFs is superior to TiO2@CNFs, and HybTi@CNFs has combined the advantages of OCTi@CNFs and TiO2@CNFs, suggesting HybTi@CNFs is an excellent electrode material for supercapacitors. (C) 2015 Elsevier Ltd. All rights reserved.</p

Secure Blockchain Middleware for Decentralized IIoT towards Industry 5.0: A Review of Architecture, Enablers, Challenges, and Directions

Resilient manufacturing is a vision in the Industry 5.0 blueprint for satisfying sustainable development goals under pandemics or the rising individualized product needs. A resilient manufacturing strategy based on the Industrial Internet of Things (IIoT) networks plays an essential role in facilitating production and supply chain recovery. IIoT contains confidential data and private information, and many security issues arise through vulnerabilities in the infrastructure. The traditional centralized IIoT framework is not only of high cost for system configuration but also vulnerable to cyber-attacks and single-point failure, which is not suitable for achieving the resilient manufacturing vision in Industry 5.0. Recently, researchers are seeking a secure solution of middleware based on blockchain technology integration for decentralized IIoT, which can effectively protect the consistency, integrity, and availability of IIoT data by utilizing the auditing and tamper-proof features of the blockchain. This paper presented a review of secure blockchain middleware for decentralized IIoT towards Industry 5.0. Firstly, the security issues of conventional IIoT solutions and the advantages of blockchain middleware are analyzed. Secondly, an architecture of secure blockchain middleware for decentralized IIoT is proposed. Finally, enabling technologies, challenges, and future directions are reviewed. The innovation of this paper is to study and discuss the distributed blockchain middleware, investigating its ability to eliminate the risk of a single point of failure via a distributed feature in the context of resilient manufacturing in Industry 5.0 and to solve the security issues from traditional centralized IIoT. Also, the four-layer architecture of blockchain middleware presented based on the IIoT application framework is a novel aspect of this review. It is expected that the paper lays a solid foundation for making IIoT blockchain middleware a new venue for Industry 5.0 research

Secure Blockchain Middleware for Decentralized IIoT towards Industry 5.0: A Review of Architecture, Enablers, Challenges, and Directions

Resilient manufacturing is a vision in the Industry 5.0 blueprint for satisfying sustainable development goals under pandemics or the rising individualized product needs. A resilient manufacturing strategy based on the Industrial Internet of Things (IIoT) networks plays an essential role in facilitating production and supply chain recovery. IIoT contains confidential data and private information, and many security issues arise through vulnerabilities in the infrastructure. The traditional centralized IIoT framework is not only of high cost for system configuration but also vulnerable to cyber-attacks and single-point failure, which is not suitable for achieving the resilient manufacturing vision in Industry 5.0. Recently, researchers are seeking a secure solution of middleware based on blockchain technology integration for decentralized IIoT, which can effectively protect the consistency, integrity, and availability of IIoT data by utilizing the auditing and tamper-proof features of the blockchain. This paper presented a review of secure blockchain middleware for decentralized IIoT towards Industry 5.0. Firstly, the security issues of conventional IIoT solutions and the advantages of blockchain middleware are analyzed. Secondly, an architecture of secure blockchain middleware for decentralized IIoT is proposed. Finally, enabling technologies, challenges, and future directions are reviewed. The innovation of this paper is to study and discuss the distributed blockchain middleware, investigating its ability to eliminate the risk of a single point of failure via a distributed feature in the context of resilient manufacturing in Industry 5.0 and to solve the security issues from traditional centralized IIoT. Also, the four-layer architecture of blockchain middleware presented based on the IIoT application framework is a novel aspect of this review. It is expected that the paper lays a solid foundation for making IIoT blockchain middleware a new venue for Industry 5.0 research

Highly Controllable and Efficient Synthesis of Mixed-Halide CsPbX₃ (X = Cl, Br, I) Perovskite QDs toward the Tunability of Entire Visible Light

CsPbX₃ (X = Cl, Br, I) perovskite quantum dots (PQDs) have been intensively investigated on photoelectric devices due to their superior optical properties. To date, the stability of CsPbX₃ PQDs is still an open challenge. The previous mixed-halide CsPbX₃ PQDs were generally obtained via the anion-exchange method at 40 °C. Here, the single- and mixed-halide CsPbX₃ PQDs are synthesized at high temperature via the hot injection technique. The surface ligands could thus be strongly coordinated onto the surface of the PQDs, which dramatically improve the optical properties of the PQDs. The resulting CsPbX₃ PQDs have high quantum yield (QY, 40–95%), narrow full width at half-maximum (FWHM) (the narrowest FWHM <10 nm), tunable band gap (408–694 nm), and highly strong photostability. The variation of their emission peaks upon anion atoms is well-supported by the theoretical band gaps calculated by the density functional theory calculations with the alloy formula correction. Hence, these PQDs show great potential as good candidates for photoelectric devices

Macropore- and Micropore-Dominated Carbon Derived from Poly(vinyl alcohol) and Polyvinylpyrrolidone for Supercapacitor and Capacitive Deionization

We developed a kind of macropore- and micropore-dominated carbon (HPAC) derived from poly­(vinyl alcohol) and polyvinylpyrrolidone for electric double-layer capacitive (EDLC) applications, e.g., supercapacitors and capacitive deionization (CDI). By comparing the EDLC performance of HPAC with those of ordered mesoporous carbon (OMC) and commercial activated carbon (AC), we evaluated the pore size effects. Cyclic voltammetry (CV) was employed for static and flowing CDI processes to identify the disparities between supercapacitors and CDI. HPAC exhibits a specific capacitance of 309 F g^–1 at a specific current of 0.5 A g^–1 (6 M KOH) in a three-electrode half-cell and has a salt removal capacity of 16.3 mg g^–1 (1.2 V, 500 mg L^–1 NaCl), which is better than those of AC and OMC. Cycling tests of HPAC in supercapacitors and CDI show excellent stability. The properties of HPAC, fine, hydrophilic, macroporous, and microporous, endow HPAC with the promising possibility of use in supercapacitors and capacitive deionization. The disparities of supercapacitors and CDI include ionic species and concentrations and solution hydromechanics. CV analysis of static and flowing CDI equipped with HPAC electrodes suggests that increasing the salt concentration in CDI is beneficial for the carbon electrode to show high capacitance and to reduce the pumping energy during the CDI process