Author
Haifeng Zhao
Other affiliations: Shihezi University, Linköping University
Bio: Haifeng Zhao is an academic researcher from University of Electronic Science and Technology of China. The author has contributed to research in topics: Quantum dot & Perovskite (structure). The author has an hindex of 9, co-authored 17 publications receiving 297 citations. Previous affiliations of Haifeng Zhao include Shihezi University & Linköping University.
Topics: Quantum dot, Perovskite (structure), Nanorod, Nanocrystal, Passivation
Papers
More filters
TL;DR: In this paper, the power conversion efficiencies (PCE) of CdS/Mn CdSe/ZnS QDs co-sensitized vertical ZnO nanorod arrays film was investigated and explained by the fact that the enhanced light absorption and reduced charge recombination by the formation of MnCdSe passivation layer covering the QDs.
74 citations
TL;DR: The incorporation of Ag NPs to TiO2/ZnO NAs photoelectrode not only increases light harvesting efficiency and facilitates exciton dissociation but also decreases surface charge recombination and prolongs electron lifetime, which collectively contribute to improving the Jsc of the CdS/CdSe QDs cosensitized solar cells.
Abstract: A high efficiency quantum dot sensitized solar cell (QDSC) based on Ag nanoparticles (NPs) decorated TiO2/ZnO nanorod arrays (NAs) photoelectrode has been constructed. The incorporation of Ag NPs to TiO2/ZnO NAs photoelectrode not only increases light harvesting efficiency and facilitates exciton dissociation but also decreases surface charge recombination and prolongs electron lifetime, which collectively contribute to improving the Jsc of the CdS/CdSe QDs cosensitized solar cells. The direct contact of Ag NPs with TiO2 NPs is undergoing Fermi level alignment; thus, the apparent Fermi level is supposed to trigger an upward shift of more negative potential, which results in an increase the Voc of the QDSCs. As a result, the power conversion efficiency of the QDSCs with Ag NPs decorated TiO2/ZnO NAs photoelectrode reached 5.92%, which is about 22% enhancement of the efficiency for the solar cells without Ag NPs (4.80%).
73 citations
45 citations
TL;DR: In this article, galvanic replacement was combined with co-reduction with reaction kinetics processes regulated to rapidly synthesize Au-Ag hollow alloy nanoparticles with tunable cavity sizes.
41 citations
TL;DR: In this paper, the authors demonstrate great potential in light-emitting diode (LED) applications due to their pure green emission and excellent stability, however, the performance of FAPbBr(3) nanocrystals has not yet reached the state-of-the-art.
Abstract: Formamidinium lead bromide (FAPbBr(3)) nanocrystals (NCs) demonstrate great potential in light-emitting diode (LED) applications due to their pure green emission and excellent stability. However, t ...
39 citations
Cited by
More filters
Ludwig Maximilian University of Munich1, University of Cambridge2, University of Hyderabad3, Katholieke Universiteit Leuven4, Massachusetts Institute of Technology5, University of Antwerp6, Indian Institute of Science7, Yantai University8, University of Vigo9, King Abdullah University of Science and Technology10, Nanjing University of Science and Technology11, Lawrence Berkeley National Laboratory12, University of California, Berkeley13, Nanyang Technological University14, Soochow University (Suzhou)15, Technische Universität München16, ETH Zurich17, Lund University18, Hokkaido University19, University of California, Santa Cruz20, Chinese Academy of Sciences21, Beijing Institute of Technology22, City University of Hong Kong23, University of Texas at Austin24, Indian Association for the Cultivation of Science25, San Diego State University26, University of Washington27, Texas A&M University28, Bilkent University29, James I University30, Max Planck Society31, National Renewable Energy Laboratory32, University of Valencia33, Shanghai Jiao Tong University34, Istituto Italiano di Tecnologia35, Swiss Federal Laboratories for Materials Science and Technology36, University of Notre Dame37, Monash University, Clayton campus38, Imperial College London39
TL;DR: A comprehensive review of metal-halide perovskite nanocrystals can be found in this article, where researchers having expertise in different fields (chemistry, physics, and device engineering) have joined together to provide a state-of-the-art overview and future prospects of metalhalide nanocrystal research.
Abstract: Metal-halide perovskites have rapidly emerged as one of the most promising materials of the 21st century, with many exciting properties and great potential for a broad range of applications, from photovoltaics to optoelectronics and photocatalysis. The ease with which metal-halide perovskites can be synthesized in the form of brightly luminescent colloidal nanocrystals, as well as their tunable and intriguing optical and electronic properties, has attracted researchers from different disciplines of science and technology. In the last few years, there has been a significant progress in the shape-controlled synthesis of perovskite nanocrystals and understanding of their properties and applications. In this comprehensive review, researchers having expertise in different fields (chemistry, physics, and device engineering) of metal-halide perovskite nanocrystals have joined together to provide a state of the art overview and future prospects of metal-halide perovskite nanocrystal research.
471 citations
TL;DR: In this paper, a one-dopant alloying strategy was proposed to generate smaller, monodisperse colloidal particles (confining electrons and holes, and boosting radiative recombination) with fewer surface defects.
Abstract: Electroluminescence efficiencies of metal halide perovskite nanocrystals (PNCs) are limited by a lack of material strategies that can both suppress the formation of defects and enhance the charge carrier confinement. Here we report a one-dopant alloying strategy that generates smaller, monodisperse colloidal particles (confining electrons and holes, and boosting radiative recombination) with fewer surface defects (reducing non-radiative recombination). Doping of guanidinium into formamidinium lead bromide PNCs yields limited bulk solubility while creating an entropy-stabilized phase in the PNCs and leading to smaller PNCs with more carrier confinement. The extra guanidinium segregates to the surface and stabilizes the undercoordinated sites. Furthermore, a surface-stabilizing 1,3,5-tris(bromomethyl)-2,4,6-triethylbenzene was applied as a bromide vacancy healing agent. The result is highly efficient PNC-based light-emitting diodes that have current efficiency of 108 cd A−1 (external quantum efficiency of 23.4%), which rises to 205 cd A−1 (external quantum efficiency of 45.5%) with a hemispherical lens. Guanidinium doping is shown to enhance the operation of perovskite nanocrystal light-emitting diodes.
450 citations
TL;DR: A comprehensive overview of the development of quantum dot-sensitized solar cells (QDSCs) is presented in this paper, including the fundamental principles, key materials in QDSCs, recombination control, and stability issues.
Abstract: Quantum dot-sensitized solar cells (QDSCs) have emerged as a promising candidate for next-generation solar cells due to the distinct optoelectronic features of quantum dot (QD) light-harvesting materials, such as high light, thermal, and moisture stability, facilely tunable absorption range, high absorption coefficient, multiple exciton generation possibility, and solution processability as well as their facile fabrication and low-cost availability. In recent years, we have witnessed a dramatic boost in the power conversion efficiency (PCE) of QDSCs from 5% to nearly 13%, which is comparable to other kinds of emerging solar cells. Both the exploration of new QD light-harvesting materials and interface engineering have contributed to this fantastically fast improvement. The outstanding development trend of QDSCs indicates their great potential as a promising candidate for next-generation photovoltaic cells. In this review article, we present a comprehensive overview of the development of QDSCs, including: (1) the fundamental principles, (2) a history of the brief evolution of QDSCs, (3) the key materials in QDSCs, (4) recombination control, and (5) stability issues. Finally, some directions that can further promote the development of QDSCs in the future are proposed to help readers grasp the challenges and opportunities for obtaining high-efficiency QDSCs.
298 citations
TL;DR: In this article, the authors focus on the significant application based advances in neat and tailored nanostructures of noble metal-metal oxide nanohybrids and touched upon chalcogenides also.
Abstract: The skilful synthesis of nanohybrids composed of noble metals (Au, Ag, Pt and Pd, as well as AuAg alloy) and metal oxides (ZnO, TiO2, Cu2O, MnO2, Fe2O3, WO3 and CeO2) has received considerable attention for applications in photocatalysis, solar cells, drug delivery, surface enhanced Raman spectroscopy and many other important areas. The overall architecture of nanocomposites is one of the most important factors dictating the physical properties of nanohybrids. Noble metals can be coupled to metal oxides and metal chalcogenides to yield diverse nanostructures, including noble metal decorated-metal oxide nanoparticles (NPs), nanoarrays, noble metal/metal oxide core/shell, noble metal/metal oxide yolk/shell and Janus noble metal–metal oxide nanostructures. In this review, we focus on the significant application based advances in neat and tailored nanostructures of noble metal–metal oxide nanohybrids and touched upon chalcogenides also. The improvement in performance in representative energy conversion, electrochemical water splitting, photocatalytic hydrogen generation, photocatalytic CO2 reduction, photocatalytic degradation of organic pollutants and dye-sensitized solar cell (DSSCs) applications is discussed. Finally, we conclude with a perspective on the future direction and prospects of these controllable nanohybrid materials.
263 citations
TL;DR: In this paper, hierarchical ZnMn2O4/ZnO nanofibers were prepared as photocatalysts by electrospinning and calcination, and the results showed that the charge separation efficiency in the composite was significantly elevated.
227 citations