Crystal engineering regulation achieving inverse temperature symmetry breaking ferroelasticity in a cationic displacement type hybrid perovskite system

Ferroelastic hybrid perovskite materials have been revealed the significance in the applications of switches,sensors,actuators,etc.However,it remains a challenge to design high-temperature ferroelastic to meet the requirements for the practical applications.Herein,we reported an one-dimensional organicinorganic hybrid perovskites(OIHP)(3-methylpyrazolium)CdCl_(3)(3-MBCC),which possesses a mmmF2/m ferroelastic phase transition at 263 K.Moreover,utilizing crystal engineering,we replace-CH_(3) with-NH_(2) and-H,which increases the intermolecular force between organic cations and inorganic frameworks.The phase transition temperature of(3-aminopyrazolium)CdCl_(3)(3-ABCC),and(pyrazolium)CdCl_(3)(BCC)increased by 73 K and 10 K,respectively.Particularly,BCC undergoes an unconventional inverse temperature symmetry breaking(ISTB)ferroelastic phase transition around 273 K.Differently,it transforms from a high symmetry low-temperature paraelastic phase(point group 2/m)to a low symmetry high-temperature ferroelastic phase(point group ī)originating from the rare mechanism of displacement of organic cations phase transition.It means that crystal BCC retains in ferroelastic phase above 273 K until melting point(446 K).Furthermore,characteristic ferroelastic domain patterns on crystal BCC are confirmed with polarized optical microscopy.Our study enriches the molecular mechanism of ferroelastics in the family of organic-inorganic hybrids and opens up a new avenue for exploring high-temperature ferroic materials.

Facet Engineering of Advanced Electrocatalysts Toward Hydrogen/Oxygen Evolution Reactions

The electrocatalytic water splitting technology can generate highpurity hydrogen without emitting carbon dioxide,which is in favor of relieving environmental pollution and energy crisis and achieving carbon neutrality.Electrocatalysts can effectively reduce the reaction energy barrier and increase the reaction efficiency.Facet engineering is considered as a promising strategy in controlling the ratio of desired crystal planes on the surface.Owing to the anisotropy,crystal planes with different orientations usually feature facet-dependent physical and chemical properties,leading to differences in the adsorption energies of oxygen or hydrogen intermediates,and thus exhibit varied electrocatalytic activity toward hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).In this review,a brief introduction of the basic concepts,fundamental understanding of the reaction mechanisms as well as key evaluating parameters for both HER and OER are provided.The formation mechanisms of the crystal facets are comprehensively overviewed aiming to give scientific theory guides to realize dominant crystal planes.Subsequently,three strategies of selective capping agent,selective etching agent,and coordination modulation to tune crystal planes are comprehensively summarized.Then,we present an overview of significant contributions of facet-engineered catalysts toward HER,OER,and overall water splitting.In particular,we highlight that density functional theory calculations play an indispensable role in unveiling the structure–activity correlation between the crystal plane and catalytic activity.Finally,the remaining challenges in facet-engineered catalysts for HER and OER are provided and future prospects for designing advanced facet-engineered electrocatalysts are discussed.

Decision Making Support System(DSS)——A Synthesized and Integrated Crystallization of Systems Engineering, Artificial Intelligence and Electronic Technologies

I firmly believe that of systems engineering is the requirement-driven force for the progress ofsoftware engineering, artificial intelligence and electronic technologies. The development ofsoftware engineering, artificial intelligence and electronic technologies is the technical supportfor the progress of systems engineering. INTEGRATION can be considered as "bridging" the ex-isting technologies and the People together into a coordinated SYSTEM.

Synthesis and Crystal Structure of a Novel Chiral 3D Metal-organic Framework Based on an N-methyl Substituted Salan Ligand

A chiral 3D metal-organic framework [CdL].DMSO＇H20 （1） was constructed by an N-methyl substituted salan ligand （H2L）, and characterized by elemental analyses, IR, TGA, powder XRD and single-crystal X-ray crystallography. 1 crystallizes in the chiral hexagonal space group P6522 with a = b = 12.2175（3）, c = 51.450（3） A, V= 6650.9（4） A3, Z = 6, Mr = 883.45, Dc = 1.323 g.cm-3, F（000） = 2760, 2（CuKa） = 1.54178 A,β = 4.771 mm-1, GOOF = 1.041, R = 0.0313 for 3901 observed reflections with I 〉 20（/） and wR = 0.0773.1 consists of three identical sets of independent 3D frameworks interpenetrated with each other. In each set of such 3D frameworks, one half of the monomer （CdL）1/2 as the building unit forms double antiparrel helical chains which are further bridged together by other （CdL）1/2 units from adjacent helical chains. All CdL units in 1 adopt A geometry. DMSO and water guest molecules are found in the gap of the interpenetrated frameworks.

A Novel Cadmium(Ⅱ) Complex Based on Asymmetric Dicarboxylate and N-Auxiliary Ligand: Synthesis, Crystal Structure and Properties

One Cd（II） complex based on dicarboxylate and N-auxiliary ligand, namely, [Cd（aip）（m-bix）]n （1, H2aip = 5-aminoisophthalic acid, m-bix = 1,3-bis（imidazol-l-yl-methyl）ben- zene）, was successfully synthesized under hydrothermal conditions. Single-crystal X-ray diffraction analysis reveals that 1 belongs to the orthorhombic system, space group Pbca with a = 14.0790（11）, b = 17.0038（15）, c = 17.3191（16）, V= 4146.1（6） A3, Z = 8, D,. = 1.698 g.cm＂3, p = 1.095 mm-1, F（000） = 2128, the final R = 0.0268 and wR = 0.0623. Complex 1 is a three-dimensional architecture with fsc-3,5-Cmce-1 topology, in which the metal ions act as rare 5-connected nodes. The TGA, XRD and luminescent properties of I were studied.

Synthesis and Crystal Structure of a Two-dimensional Cadmium Complex Based on Terephthalate and 1-Methyl-2,2'-bibenzimidazole

The title complex, [Cd（MeHbibzim）（1,4-bdc）]n （1, MelToibzim = 1-methyl-2,2＇- bibenzimidazole, 1,4-bdc = terephthalate）, was synthesized with hydrothermal reactions. The compound crystallizes in monoclinic, space group C2/c with a = 9.822（4）, b = 18.510（7）, c = 22.372（9） A, β = 98.359（6）°, C23H16CdN4O4, Mr = 524.81, V= 4024（3） A3, Z = 8, Dc. = 1.733 g/cm3, μ（MoKa） = 1.126 mm-1, F（000） = 2096, the final R = 0.0597 and wR = 0.1374 for 3906 observed reflections （1 〉 2σ（I））. X-ray diffraction analysis reveals that the Cd atom is coordinated by two nitrogen atoms from the chelating MeHbibzim and three carboxyl oxygen atoms from three terephthalate ligands, thus forming a distorted square pyramidal coordination sphere, [CdN2O3]. Every two Cd atoms are linked together via two carboxyl groups into a dinuclear unit with Cd...Cd separation of 3.806（4） A. The dinuclear building units are linked by terephthalate ligands into two-dimensional layers, which are further aggregated into a 3D framework via hydrogen bonding interactions.

Syntheses and Crystal Structures of Two New Supramolecular Architectures Constructed from the Main Group Metal Chloride and Protonated 2-(3-Pyridyl)benzimidazole

The reactions of SbCl3 and HgCl2 with 2-（3-pyridyl）benzimidazole （PyBIm） in solution acidified with HCl have been investigated. The PyBIm ligands are protonated into 2-（3-pyridinio）benzimidazolium （H2PyBIm） cations and the corresponding metal ions are bonded with chloride atoms into coordination anions, forming two new coordination compounds, namely, （H2PyBIm）（SbCl5） 1 and （H2PyBIm）2（Hg2Cl8） 2. Both compounds were characterized by X-ray crystallography. Crystal data for 1： triclinic, space group P1^- with a = 5.7030（7）, b = 9.0625（11）, c = 16.5929（18） A, α = 91.808（7）°, β = 93.234（6）, γ = 99.216（7）°, C12H11N3SbCl5, Mr = 496.24, V = 844.44（17） A^3, Z = 2, Dc = 1.952 g/cm^3, μ（MoKα） = 2.419 mm^-1, F（000） = 480, the final R = 0.0496 and wR = 0.1382 for 3433 observed reflections （I 〉 2σ（I））. Crystal data for 2： monoclinic, space group P21/c with a = 7.8061（5）, b = 15.8127（9）, c = 12.2435（9） , β = 91.955（4）o, C24H22N6Hg2Cl8, Mr = 1079.26, V = 1510.40（17） 3, Z = 2, Dc = 2.373 g/cm3, μ（MoKα） = 10.889 mm-1, F（000） = 1008, the final R = 0.0293 and wR = 0.0562 for 2854 observed reflections （I 〉 2σ（I））. X-ray diffraction analysis reveals that the antimony（III） is five-coordinated, exhibiting a slightly distorted square-pyramidal coordination geometry; while in 2, a dimeric [Hg2Cl8]^4-anion consists of two trigonal bipyramids sharing two common edges. The organic cations and coordination anions are connected into a one-dimensional belt and a two-dimensional sheet through N-H···Cl hydrogen bonding interactions in compounds 1 and 2, respectively; both are further aggregated into 3D frameworks by strong π-π contacts.

A Novel Neodymium-tartrate Complex with Distinctive Rare Topology:Hydrothermal Synthesis and Crystal Structure

One novel neodymium-tartrate complex exhibiting distinctive rare topology,name-ly,[Nd（TTA）1.5（H2O）]·H2O（1,H2TTA = tartaric acid）,was successfully synthesized by the reaction of neodymium-oxide with H2TTA under hydrothermal conditions.Single-crystal X-ray diffraction analysis reveals that 1 belongs to the monoclinic system,space group P21/c with a = 6.0357（13）,b = 7.6106（17）,c = 24.389（5） ,β = 100.136（5）°,V = 1102.8（4） 3,Z = 4,Dc = 2.423 g·cm-3,μ = 4.763 mm-1,F（000） = 776,the final R = 0.0689 and wR = 0.2191.In complex 1,the 2D layer consisting of μ4-ligands and 4-connected Nd（III） centers is a rare example of uni-nodal net of（42.64） topology.The 2D layers are further connected by μ2-TTA2-ligands to give a 3D（42.64）（42.67.8） topological structure,where the Nd（III） atoms act as rare 5-connected topological blocks.

Synthesis and Crystal Structure of a Cobalt(Ⅱ)Complex Based on 2,2-Bibenzimidazole and N,N-bis(phosphonomethyl)aminoacetic Acid

The title complex, [Co2（bibzim）（H2bibzim）4]·Co2（H2bibzim）2（Hbibzim）（HL）]2- 2H2O （1） （HEbibzim = 2,2＇-bibenzimidazole, H5L = N,N-bis（phosphonomethyl）aminoacetic acid （HO2CCH2N（CH2PO3H2）2））, was synthesized with hydrothermal reactions. The compound crystallizes in triclinic, space group P1 with a = 13.71020（10）, b = 14.9165（5）, c = 20.9924（5） A, a = 86.344（9）, β = 71.214（8）, γ = 73.757（7）°, C162HI24Co6N46O18P4, Mr = 3478.52, V = 3900.55（16） A3, Z = 2, Dc = 1.482 g/cm3,μ（MoKa） = 0.747 mm^-1, F（000） = 1784, the final R = 0.0777 and wR = 0.2091 for 13598 observed reflections （I 〉 2σ（I））. X-ray diffraction analysis reveals that there are three crystallographically independent Co（II） atoms in the complex. The complex consists of binuclear coordination cation, binuclear coordination anion, as well as lattice water molecules, which further aggregate into a 3D framework via hydrogen bonding as well as π-π interactions.

Engineering intermolecular charge transfer in chiral organometallic crystals by rational doping for high-contrast CPL switches

The development of circularly polarized luminescence(CPL)switches is of great importance but challenging.Herein,a charge donor/acceptor pair comprising two chiral gold(I)-isocyanide complexes was designed to construct light-harvesting system via intermolecular charge-transfer(CT)interactions.By doping nonemissive S-Au I into blue-emitting S-AuCN,(S-Au CN)_(1-x)(S-AuI)_(x)(0≤x≤3.4%)with tunable emission from blue to red was achieved.This large red-shifted emission was realized based on the remarkable change of the electronic properties between the S-Au CN dimer and red-emitting(S-A CN)-(S-AuI)CT pair,and the resulting energy-transfer(En T)process between them.Importantly,the En T process can be switched off/on by external stimuli of grinding and CH_(2)Cl_(2)fuming,giving rise to high-contrast(blue versus red)CPL switching properties.This study opens a novel avenue for developing CPL switches by constructing light-harvesting CT-doped systems based on chiral organometallic complexes.

Lanthanide Complex [Nd(dpdo)_4(H_2O)_3][ClO_4]_3·4.5H_2O·dpdo Containing Framework Based on 4,4′-Dipyradine-Dioxide

A novel lanthanide coordination polymer formulated as [Nd(dpdo) 4(H 2O) 3] 3·4.5H 2O·dpdo 1(dpdo=4,4′-dipyrazine-dioxide) was synthesized and structurally characterized. The Nd 3+ ions are bridged by dpdo ligands in a cis-mode to form a zigzag chain along direction. Meanwhile, each Nd 3+ ion is coordinated with three terminal dpdo molecules. One of them is overlapped with the bridging one through π-π stackings, and the other two are bound to the opposite directions of the bridging ones, producing a ribbon-like motif with rectangular cavity. These adjacent ribbons are connected through inter-molecular π-π stackings to give parquet-like architecture with a large rectangular channel (1.108 nm×1.660 nm) in which the crystal lattice water molecules and ClO 4 - anions are included. Thermal analysis shows that the solvate dpdo and water molecules can be removed at lower temperature, while coordinated dpdo molecules are lost simultaneously at higher temperature.

High-performance and broadband photodetection of bicrystalline(GaN)_(1-x)(ZnO)_(x)solid solution nanowires via crystal defect engineering

Crystal defect engineering is widely used as an effective approach to regulate the optical and optoelectronic properties of semiconductor nanostructures.However,photogenerated electron-hole pair recombination centers caused by structural defects usually lead to the reduction of optoelectronic performance.In this work,a high-performance photodetector based on(GaN)_(1-x)(ZnO)_(x)solid solution nanowire with bicrystal structure is fabricated and it shows excellent photoresponse to ultraviolet and visible light.The highest responsivity of the photodetector is as high as 60,86 and 43 A/W under the irradiation of365 nm,532 nm and 650 nm,respectively.The corresponding response time is as fast as 170,320 and 160 ms.Such wide spectral responses can be attributed to various intermediate energy levels induced by the introduction of various structural defects and dopants in the solid solution nanowire.Moreover,the peculiar bicrystal boundary along the axial direction of the nanowire provides two parallel and fast transmission channels for photo-generated carriers,reducing the recombination of photo-generated carriers.Our findings provide a valued example using crystal defect engineering to broaden the photoresponse range and improve the photodetector performance and thus can be extended to other material systems for various optoelectronic applications.

Crystal plane engineering of MAPbI_(3) in epoxy-based materials for superior gamma-ray shielding performance

The rapid development of the aerospace and nuclear industries is accompanied by increased exposure to high-energy ionising radiation.Thus,the performance of radiation shielding materials needs to be improved to extend the service life of detectors and ensure the safety of personnel.The development of novel lightweight materials with high electron density has therefore become urgent to alleviate radiation risks.In this work,new MAPbI_(3)/epoxy(CH 3NH 3PbI 3/epoxy)composites were prepared via a crystal plane engineering strategy.These composites delivered excellent radiation shielding performance against 59.5 keV gamma rays.A high linear attenuation coefficient(1.887 cm−1)and mass attenuation coefficient(1.352 cm2 g−1)were achieved for a representative MAPbI_(3)/epoxy composite,which was 10 times higher than that of the epoxy.Theoretical calculations indicate that the electron density of MAPbI_(3)/epoxy composites significantly increases when the content ratio of the(110)plane in MAPbI_(3) increases.As a result,the chances of collision between the incident gamma rays and electrons in the MAPbI_(3)/epoxy composites were enhanced.The present work provides a novel strategy for designing and developing high-efficiency radiation shielding materials.

Bio-inspired high-efficiency photosystem by synergistic effects of core-shell structured Au@CdS nanoparticles and their engineered location on{001}facets of SrTiO_(3)nanocrystals

Natural photosynthesis,which provides a green and high-efficiency energy conversion path by spatial separation of photogenerated carriers through combined actions of molecules ingeniously arranged in an efficient solar nanospace,highlights the importance of rational nanostructure design to realize artificial high-efficiency photosystem.Inspired by these unique features,we constructed a high-efficiency ternary photosystem by selectively decorating the{001}facets of 18-facet SrTiO_(3)with Au@CdS photosensitizers via a green photo-assisted method.Benefiting from the dual-facilitated charge carriers transportation in core-shell structured Au@CdS heterojunction and well-faceted 18-facet SrTiO_(3)nanocrystal,such a photo-catalyst could realize the effective spatial separation of photogenerated electrons and holes.As expected,the 18-facet SrTiO_(3)/Au@CdS photocatalyst exhibits superior activity in visible-light-driven photocatalytic hydrogen evolution(4.61 mmol h^(−1)g^(−1)),166%improvement in comparison with randomly deposited Au@CdS(1.73 mmol h^(−1)g^(−1)).This work offers new insight into the development of green and high-efficiency photocatalytic systems based on the rational nanostructure design by crystal facet engineering.

基于雷洛昔芬的多重刺激响应性单组分室温磷光分子晶体

Simultaneously achieving room-temperature phosphorescence(RTP) and multiple-stimuli responsiveness in a single-component system is of significance but remains challenging. Crystallization has been recognized to be a workable strategy to fulfill the above task. However, how the molecular packing mode affects the intersystem crossing and RTP lifetime concurrently remains unclear so far. Herein, four economic small-molecular compounds, analogues of the famous drug raloxifene(RALO), are facilely synthesized and further explored as neat single-component and stimuli-responsive RTP emitters via crystallization engineering. Thanks to their simple structures and high ease to crystallize, these raloxifene analogues function as models to clarify the important role of molecular packing in the RTP and stimuliresponsiveness properties. Thorough combination of the single-crystal structure analysis and theoretical calculations clearly manifests that the tight antiparallel molecular packing mode is the key point to their RTP behaviors. Interestingly, harnessing the controllable and reversible phase transitions of the two polymorphs of RALO-OAc driven by mechanical force, solvent vapor, and heat, a single-component multilevel stimuli-responsive platform with tunable emission color is established and further exploited for optical information encryption. This work would shed light on the rational design of multi-stimuli responsive RTP systems based on single-component organics.

Excellentπ-Bowl Semiconductors Based on C_(70)Subunit

As open substructures of fullerenes,aromaticπ-bowls are promising candidates as new organic semiconductors,as well as attractive hosts for fullerenes.We demonstrate herein the synthesis and characterization of a novel C_(2v)symmetricπ-bowl,pyracyleno[6,5,4,3,2,1-pqrstuv]pentaphene(3).Bowl 3 was equipped with two distinctive reactive sites,allowing for bromination and cross-coupling reactions to readily yield functionalized bowls with two 2,4,6-trimethylphenyl(5)and triethylsilyl(TES)-ethynyl(6)substituents,respectively.Variable-temperature 1H NMR analysis and density functional theory(DFT)calculations indicated bowl-to-bowl inversions of 3,5,and 6 at room temperature.By alternating the substituents,the crystal structures of the threeπ-bowls 3,5,and 6 could be controlled from 1D linear to 1D slipped to 2D herringbone packing motifs,providing insight into the packing behavior ofπ-bowls.1H NMR titration study indicated that the TES-ethynyl substituent enhanced the ability ofπ-bowl to bind C_(70)with an association constant of 2485 M−1.The C_(70)molecules withπ-bowls 3 and 6 formed 1:1 complexes,in which C_(70)molecules aggregated into zig-zag and 1D linear arrays,respectively.The hole mobility of 2.3 cm^(2)V^(−1)^s(−1)and electron mobility of 0.16 cm^(2)V^(−1)^s(−1)ofπ-bowl 3 and its complex with C_(70)were demonstrated,respectively,which proved a great value for the development of aromaticπ-bowl semiconductors with tunable properties for organic electronic devices.

Phase Engineering of CoMo0_(4)Anode Materials toward Improved Cycle Life for Li^(+)Storage

Anode materials based on conversion reactions usually possess high energy densities for lithium-ion batteries(LIBs).However,they suffer from poor rate performance and cycle life due to serious volume changes.Herein,α/β-CoMo04 heterogeneous nanorods are synthesized via a facile co-precipitation method,and further are phase-engineered through varying calcination temperature,accomplishing the obviously improved cycle life and rate performance as anodes for LIBs.When evaluated at a current density of 1.0 A·g^(-1)the optimal nanorods with anα/βphase ratio of 6.0 afford the reversible capacity of 1143.6 mAh·g^(-1)after 200 cycles,outperforming most of recently reported bimetal oxides.Li^(+)storage mechanism is further analyzed by using in-situ X-ray diffraction and ex-situ transition electronic microscopy.It's revealed thatβ-CoMoO_(4)follows a one-step conversion reaction;whileα-CoMo0_(4)proceeds an intercalation pathway before the conversion reaction.Grading storage of Li^(+)would alleviate the volume effect of heterostructuredα/β-CoMo0_(4),forming electronically conductive network evenly composed of Co and Mo nanograins to enable the reversible electrochemical conversion.This work is anticipated to give some hints for the rational design of high-performance energy materials.

Engineering Heteronuclear Arrays from Ir^(Ⅲ)-Metalloligand and Co^(Ⅱ)Showing Coexistence of Slow Magnetization Relaxation and Photoluminescence

Three heteronuclear Ir^(Ⅲ)-Co^(Ⅱ)arrays,[Co(H_(2)O)6]_(2)[Ir(ppyCOO)(ppyCOOH)(bpy)]_(2)[Ir(ppyCOO)_(2)(bpy)]_(2)(NO_(3))2·10.5H_(2)O(2),[Co(H_(2)O)6]{Co-(H_(2)O)4[Ir(ppyCOO)_(2)(bpy)]_(2)}[Ir(ppyCOO)_(2)(bpy)]2·15H_(2)O(3)and{Co(H_(2)O)2[Ir(ppyCOO)_(2)(bpy)]_(2)}·2CH_(3)OH·3H_(2)O(4),have been synthe-sized by combining paramagnetic Co^(Ⅱ)ion with luminescent Ir^(Ⅲ)-metalloligand,[Ir(ppyCOOH)_(2)(bpy)][Ir(ppyCOO)_(2)(bpy)]·5H_(2)O(1),where ppyCOOH=3-(pyridin-2-yl)benzoic acid and bpy=2,2'-bipyridyl.Owing to the variable charged states of compound 1 at dif-ferent pH,compounds 2 and 3 are discrete ionic complexes containing hydrated Co^(2+)cations and deprotonated[Ir(ppyCOO)_(2)(bpy)]-anions as well as coexisting neutral[Ir(ppyCOO)(ppyCOOH)(bpy)](for 2)or Co(H_(2)O)_(4)[Ir(ppyCOO)_(2)(bpy)]_(2) trinuclear molecule(for 3).Whereas compound 4 consists of self-assembled two-dimensional coordination polymer with Co-metalloligand dative bonds.The hexa-coordinated Co^(Ⅱ)cores in all complexes display octahedral geometries with varying degrees of distortion.In a bias dc field,the ac susceptibilities for 2-4 reveal slow magnetic relaxation.Moreover,the solid-state phosphorescence is observed for compounds 2 and 3 due to weak supramolecular interaction between Co^(Ⅱ)ion and Ir-moiety but is severely quenched for 4,where the Co center is strongly connected to the metalloligand.To the best of our knowledge,this is the first report of Ir-Co systems showing both slow magnetization relaxation and photoluminescence.

New Crystalline Forms of Mebendazole with n-Alkyl Carboxylic Acids Neutral and Ionic Status

Structural information on the crystalline forms of mebendazole, an anti-parasitic drug, is limited, although three polymorphic forms of this drug have been reported. The present work investigates the structures and properties of different crystalline forms of mebendazole with a series of n-alkyl carboxylic acids, including trifluroacetic acid （1）, formic acid （2）, acetic acid （3）, propanoic acid （4）, butanoic acid （5）, valeric acid （6） and hexanoic acid （7）. These compounds were characterized by thermogravimetric analysis, IR spectra, as well as powder and single-crystal X-ray diffraction analysis. The R22（8） structural motif was detected in all the seven products, which was formed by a pair of N--H…O/O--H…N hydrogen bonds between mebendazole and carboxylic acid. Forms 3--7 were found to be neutral solvate, while in forms 1 and 2, proton transfer was observed from carboxylic acid to mebendazole.

Tailoring crystal polymorphs of organic semiconductors towards high-performance field-effect transistors

As a quite ubiquitous phenomenon,crystal polymorph is one of the key issues in the field of organic semiconductors.This review gives a brief summary to the advances on polymorph control of thin film and single crystal of representative organic semiconductors towards high-performance field-effect transistors.Particularly,the relationship between crystal polymporh and charge transport behaviour has been discussed to shed light on the rational preparation of outstanding organic semiconducting materials with desired crystal polymorph.