Targeted transfer of self-assembled CdSe nanoplatelet film onto WS_(2) flakes to construct hybrid heterostructures

Colloidal CdSe nanoplatelets are thin semiconductor materials with atomic flatness surfaces and one-dimensional strong quantum confinement,and hence they own very narrow and anisotropic emission.Here,we present a polydimethylsiloxane(PDMS)assisted transferring method that can pick up single layer CdSe nanoplatelet films self-assembled on a liquid surface and then precisely transfer to a target.By layer-by-layer picking up and transferring,multiple layers of CdSe films can be built up to form CdSe stacks with each single layer having dominant in-plane transition dipole distribution,which both material and energic structures are analogous to traditional multiple quantum wells grown by molecular-beam epitaxy.Additionally,with the great flexibility of colloidal nanoplatelets and this transferring method,CdSe nanoplatelets films can be combined with other materials to form hybrid heterostructures.We transferred a single-layer CdSe film onto WS_(2) flakes,and precisely studied the fast energy transfer rate with controlled CdSe nanoplatelet orientation and by using a streak camera with a ps time resolution.

Construction of a High-Quality Organic-Inorganic Hybrid Heterostructure and Its Photo-response Performance

The combination of metal oxide and organic semiconductor for constructing organic-inorganic hybrid heterostructure is promising to offer unique optoelectronic properties.However,the distinct difference in electron structure and processing technology of the two types of materials makes it usually difficult to fully deliver their complementary advantages.Herein,we report the construction of a high quality organic/In_(2)O_(3) hybrid heterostructure presenting a good ambipolar transport with average electron mobility>1 cm^(2)V^(-1)·s^(-1) and hole mobility up to 0.4 cm^(2)·V^(-1)·s^(-1),respectively,together with a high-gain inverter.In addition,the incorporation with organic film on top of In_(2)O_(3) remarkably reduces the dark current,enabling the realization of high photoconductivity response with photo-sensitivity of two magnitudes higher than that of pure In2O3.The photoconductor and phototransistor of the hybrid structure demonstrate high photoresponsivity>10^(3) AW^(-1) and detectivity up to 10^(14) Jones,demonstrating the promising functionality of such a high quality hybrid heterostructure.

Ultrahigh-temperature ferromagnetism in MoS_(2) Moirésuperlattice/graphene hybrid heterostructures

Realizing high-temperature ferromagnetism in two-dimensional(2D)semiconductor nanosheets is significant for their applications in next-generation magnetic and electronic nanodevices.Herein,this goal could be achieved on a MoS_(2) Moirésuperlattice grown on the reduced graphene oxide(RGO)substrate by a hydrothermal approach.The as-synthesized bilayer MoS_(2) superlattice structure with rotating angle(ϕ=13°±1°)of two hexagonal MoS_(2) lattices,possesses outstanding ferromagnetic property and an ultra-high Curie temperature of 990 K.The X-ray absorption near-edge structure and ultraviolet photoelectron spectroscopies combined with density functional theory calculation indicate that the covalent interactions between MoS_(2) Moirésuperlattice and RGO substrate lead to the formation of interfacial Mo-S-C bonds and complete spin polarization of Mo 4d electrons near the Fermi level.This design could be generalized and may open up a possibility for tailoring the magnetism of other 2D materials.

Hybrid 1D/2D heterostructure with electronic structure engineering toward high-sensitivity and polarization-dependent photodetector

The widespread application of photodetectors has triggered an urgent need for high-sensitivity and polarization-dependent photodetection.In this field,the two-dimensional(2D)tungsten disulfide(WS_(2))exhibits intriguing optical and electronic properties,making it an attractive photosensitive material for optoelectronic applications.However,the lack of an effective built-in electric field and photoconductive gain mechanism in 2D WS_(2)impedes its application in high-performance photodetectors.Herein,we propose a hybrid heterostructure photodetector that contains 1D Te and 2D WS_(2).In this device,1D Te induces in-plane strain in 2D WS_(2),which regulates the electronic structures of local WS_(2)and gives rise to type-Ⅱ band alignment in the horizontal direction.Moreover,the vertical heterojunction built of 2D WS_(2)and 1D Te introduces a high photoconductive gain.Benefiting from these two effects,the transfer of photogenerated carriers is optimized,and the proposed photodetector exhibits high sensitivity(photoresponsivity of ~27.7 A W^(-1),detectivity of 9.5×10^(12)Jones,and short rise/decay time of 19.3/17.6 ms).In addition,anisotropic photodetection characteristics with a dichroic ratio up to 2.1 are achieved.This hybrid 1D/2D heterostructure overcomes the inherent limitations of each material and realizes novel properties,opening up a new avenue towards constructing multifunctional optoelectronic devices.

Recent progress in optoelectronic applications of hybrid 2D/3D silicon-based heterostructures

Silicon-based semiconductor technology has made great breakthroughs in the past few decades,but it is reaching the physical limits of Moore’s law.In recent years,the presence of two-dimensional(2 D)materials was regarded as an opportunity to break the limitation of traditional siliconbased optoelectronic devices owing to their special structure and superior properties.In consideration of the widely studied hybrid integration of 2 D material detectors and 3 D siliconbased systems,in this paper,the basic properties of several 2 D materials used in photodetectors are summarized.Subsequently,the progress in silicon photonic integrated photodetectors based on 2 D materials is reviewed,followed by the summarization of the device structure and main performances.Then,the combination of some other traditional and2 D devices is discussed as a supplement.Finally,the prospective development of the hybrid 2 D/3 D silicon-based heterostructures is expected.

Engineering heterointerfaces coupled with oxygen vacancies in lanthanum–based hollow microspheres for synergistically enhanced oxygen electrocatalysis

The development of high–efficiency and low–cost bifunctional oxygen electrocatalysts is critical to enlarge application of zinc–air batteries(ZABs). However, it still remains challenges due to their uncontrollable factor at atomic level during the catalysts preparation, which requires the precise regulation of active sites and structure engineering to accelerate the reaction kinetics for both oxygen reduction reaction(ORR) and oxygen evolution reaction(OER). Herein, a novel Co–doped mixed lanthanum oxide and hydroxide heterostructure(termed as Co–La MOH|OV@NC) was synthesized by pyrolysis of La–MOF–NH_(2) with spontaneous cobalt doping. Synergistic coupling of its hollow structure, doping effect and abundant oxygen vacancies creates more active sites and leads to higher electroconductivity, which contribute to the better performance. As employed as a bifunctional oxygen electrocatalyst, the resulting 3 Co–La MOH|OV@NC exhibits superior electrocatalytic activity for both ORR and OER. In assembled ZAB, it also demonstrates an excellent power density of 110.5 m W cm^(-2), high specific capacity of 810 m Ah g_(Zn)^(-1), and good stability over 100 h than those of Pt/C + RuO_(2). Density functional theory(DFT) calculation reveals that the heterointerfaces coupled with oxygen vacancies lead to an enhanced charge state and electronic structure, which may optimize the conductivity, charge transfer, and the reaction process of catalysts.This study provides a new strategy for designing highly efficient bifunctional oxygen electrocatalysts based on rare earth oxide and hydroxides heterointerface.

Porous g-C_(3)N_(4)-encapsulated TiO_(2) hollow sphere as a high-performance Z-scheme hybrid for solar-induced photocatalytic abatement of environmentally toxic pharmaceuticals

Herein,we rationally constructed a hybrid heterostructure comprising porous g-C_(3)N_(4)(CN)-encapsulated anatase TiO_(2) hollow spheres(TOHS)via a synthesis method that involves hydrothermal and calcination treatments.The fabricated hybrid,termed CN/TOHS,demonstrated extraordinary activity toward the degradation of environmentally toxic pharmaceutical substances(acetaminophen and ciprofloxacin)in aqueous solutions under simulated sunlight irradiation;the activity of CN/TOHS was superior to that attained for individual TOHS and CN counterparts.In particular,the CN/TOHS hybrid containing 13.3 wt.%of CN on TOHS displayed the optimum degradation activity among the tested catalysts used in this study,and it also possessed exceptional recyclability and stability during consecutive degradation tests.The remarkable photocatalytic activity and stability of the hybrid were predominantly ascribed to the large solid interfacial contact between constituents,TOHS and CN,induced by effective hybrid structure,which boosted the interfacial charge transfer and impeded with the direct recombination of photo-induced charges.Notably,the results of the liquid chromatography-mass spectrometry analysis corroborated the effective mineralization of model pharmaceutical pollutants in the presence of the CN/TOHS hybrid.The simple interfacial engineering strategy presented in this study offers a potential route for the rational design of novel catalysts for application in environmental remediation and solar energy conversion.