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Jiang-Gao Mao

Bio: Jiang-Gao Mao is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Crystal structure & Isostructural. The author has an hindex of 53, co-authored 401 publications receiving 10534 citations. Previous affiliations of Jiang-Gao Mao include Hong Kong Baptist University & The Chinese University of Hong Kong.


Papers
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Journal ArticleDOI
TL;DR: Pb-layered perovskite (benzylammonium)2PbCl4 is ferroelectric with semiconducting behaviours, and this finding throws light on the new properties of the hybrid organo-plumbate or stannate compounds and provides a new way to develop new semiconductor ferroelectrics.
Abstract: Inorganic semiconductor ferroelectrics such as BiFeO3 have shown great potential in photovoltaic and other applications. Currently, semiconducting properties and the corresponding application in optoelectronic devices of hybrid organo-plumbate or stannate are a hot topic of academic research; more and more of such hybrids have been synthesized. Structurally, these hybrids are suitable for exploration of ferroelectricity. Therefore, the design of molecular ferroelectric semiconductors based on these hybrids provides a possibility to obtain new or high-performance semiconductor ferroelectrics. Here we investigated Pb-layered perovskites, and found the layer perovskite (benzylammonium)2PbCl4 is ferroelectric with semiconducting behaviours. It has a larger ferroelectric spontaneous polarization Ps=13 μC cm(-2) and a higher Curie temperature Tc=438 K with a band gap of 3.65 eV. This finding throws light on the new properties of the hybrid organo-plumbate or stannate compounds and provides a new way to develop new semiconductor ferroelectrics.

466 citations

Journal ArticleDOI
TL;DR: In this paper, two types of synthetic techniques were applied: attaching various functional groups or introducing a second metal linker to the phosphonate ligand, lanthanide phosphonates with 0D, 1D, 2D and 3D structures have been isolated.

353 citations

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TL;DR: A new second-order NLO material, Se2B2O7, with a SHG efficiency of about 2.2 times that of KDP (KH2PO4), is discovered in the selenite-borate system.
Abstract: Exploration on the compounds in the selenite−borate system led to the discovery of a new second-order NLO material, Se2B2O7, with a SHG efficiency of about 2.2 times that of KDP (KH2PO4). Its structure features a 3D network with helical tunnels, and it is transparent in the UV and visible region. The compound is a wide band gap semiconductor.

322 citations

Journal ArticleDOI
TL;DR: A new SHG material, BaNbO(IO(3))(5), has been prepared that exhibits a very large SHG response and is phase-matchable and has high thermal stability and a wide transparent region.
Abstract: By combination of Nb5+ (having a d0 electronic configuration) and the lone-pair-containing iodate anion, a new SHG material, BaNbO(IO3)5, has been prepared. It exhibits a very large SHG response (∼14 times that of KH2PO4 and ∼660 times that of α-SiO2) and is phase-matchable. The material has high thermal stability and a wide transparent region.

281 citations

Journal ArticleDOI
TL;DR: By adjusting the composition x, the bandgap is successfully tuned from previously reported 3.65 eV to as low as 2.74 eV, and the excellent ferroelectricity was kept intact and may contribute to improving the photoelectronic and/or photovoltaic performance of hybrid perovskite-type compounds.
Abstract: Semiconducting ferroelectricity is realized in hybrid perovskite-type compounds (cyclohexylammonium)2 PbBr4-4 x I4 x (x = 0-1). By adjusting the composition x, the bandgap is successfully tuned from previously reported 3.65 eV to as low as 2.74 eV, and the excellent ferroelectricity was kept intact. This finding may contribute to improving the photoelectronic and/or photovoltaic performance of hybrid perovskite-type compounds.

271 citations


Cited by
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Journal ArticleDOI
TL;DR: One-year stable perovskite devices are shown by engineering an ultra-stable 2D/3D (HOOC(CH2)4NH3)2PbI4/CH3NH3Pb mezzanine junction, which will enable the timely commercialization of perovSKite solar cells.
Abstract: Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly stable under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year stable perovskite devices by engineering an ultra-stable 2D/3D (HOOC(CH2)4NH3)2PbI4/CH3NH3PbI3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency stable for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative stable and low-cost architecture will enable the timely commercialization of perovskite solar cells. Up-scaling represents a key challenge for photovoltaics based on metal halide perovskites. Using a composite of 2D and 3D perovskites in combination with a printable carbon black/graphite counter electrode; Granciniet al., report 11.2% efficient modules stable over 10,000 hours.

1,531 citations

Journal ArticleDOI
TL;DR: This critical review focuses on anode materials composed of Group IV and V elements with their composites including Ag and Mg metals as well as transition metal oxides which have been intensively investigated.
Abstract: Research to develop alternative electrode materials with high energy densities in Li-ion batteries has been actively pursued to satisfy the power demands for electronic devices and hybrid electric vehicles. This critical review focuses on anode materials composed of Group IV and V elements with their composites including Ag and Mg metals as well as transition metal oxides which have been intensively investigated. This critical review is devoted mainly to their electrochemical performances and reaction mechanisms (313 references).

1,497 citations

Journal ArticleDOI
TL;DR: Polyoxometalates (POMs) are discrete anionic metaloxygen clusters which can be regarded as soluble oxide fragments which play a great role in various areas ranging from catalysis, medicine, electrochemistry, photochromism,5 to magnetism.
Abstract: Polyoxometalates (POMs) are discrete anionic metaloxygen clusters which can be regarded as soluble oxide fragments. They exhibit a great diversity of sizes, nuclearities, and shapes. They are built from the connection of {MOx} polyhedra, M being a d-block element in high oxidation state, usually VIV,V, MoVI, or WVI.1 While these species have been known for almost two centuries, they still attract much interest partly based on their large domains of applications. They play a great role in various areas ranging from catalysis,2 medicine,3 electrochemistry,4 photochromism,5 to magnetism.6 This palette of applications is intrinsically due to the combination of their added value properties (redox properties, large sizes, high negative charges, nucleophilicity...). Parallel to this domain, the organic-inorganic hybrids area has followed a similar expansion during the last 10 years. The concept of organic-inorganic hybrid materials * To whom correspondence should be addressed. E-mail: dolbecq@ chimie.uvsq.fr. Chem. Rev. 2010, 110, 6009–6048 6009

1,475 citations

Journal ArticleDOI
TL;DR: In this paper, a large scale synthesis, crystal structure, and optical characterization of the 2D (CH3(CH2)3NH3)n−1PbnI3n+1 (n = 1, 2, 3, 4, ∞) perovskites is presented.
Abstract: The hybrid two-dimensional (2D) halide perovskites have recently drawn significant interest because they can serve as excellent photoabsorbers in perovskite solar cells. Here we present the large scale synthesis, crystal structure, and optical characterization of the 2D (CH3(CH2)3NH3)2(CH3NH3)n−1PbnI3n+1 (n = 1, 2, 3, 4, ∞) perovskites, a family of layered compounds with tunable semiconductor characteristics. These materials consist of well-defined inorganic perovskite layers intercalated with bulky butylammonium cations that act as spacers between these fragments, adopting the crystal structure of the Ruddlesden–Popper type. We find that the perovskite thickness (n) can be synthetically controlled by adjusting the ratio between the spacer cation and the small organic cation, thus allowing the isolation of compounds in pure form and large scale. The orthorhombic crystal structures of (CH3(CH2)3NH3)2(CH3NH3)Pb2I7 (n = 2, Cc2m; a = 8.9470(4), b = 39.347(2) A, c = 8.8589(6)), (CH3(CH2)3NH3)2(CH3NH3)2Pb3I10 (...

1,451 citations