Searching for light and miniaturized functional device structures for sustainable energy gathering from the environment is the focus of energy society with the development of the internet of things.The proposal of a d...Searching for light and miniaturized functional device structures for sustainable energy gathering from the environment is the focus of energy society with the development of the internet of things.The proposal of a dynamic heterojunction-based direct current generator builds up new platforms for developing in situ energy.However,the requirement of different semiconductors in dynamic heterojunction is too complex to wide applications,generating energy loss for crystal structure mismatch.Herein,dynamic homojunction generators are explored,with the same semiconductor and majority carrier type.Systematic experiments reveal that the majority of carrier directional separation originates from the breaking symmetry between carrier distribution,leading to the rebounding effect of carriers by the interfacial electric field.Strikingly,NN Si homojunction with different Fermi levels can also output the electricity with higher current density than PP/PN homojunction,attributing to higher carrier mobility.The current density is as high as 214.0 A/m^(2),and internal impedance is as low as 3.6 kΩ,matching well with the impedance of electron components.Furthermore,the N-i-N structure is explored,whose output voltage can be further improved to 1.3V in the case of the N-Si/Al2O3/N-Si structure,attributing to the enhanced interfacial barrier.This approach provides a simple and feasible way of converting low-frequency disordered mechanical motion into electricity.展开更多
Static heterojunction-based electronic devices have been widely applied because carrier dynamic processes between semiconductors can be designed through band gap engineering.Herein,we demonstrate a tunable direct-curr...Static heterojunction-based electronic devices have been widely applied because carrier dynamic processes between semiconductors can be designed through band gap engineering.Herein,we demonstrate a tunable direct-current generator based on the dynamic heterojunction,whose mechanism is based on breaking the symmetry of drift and diffusion currents and rebounding hot carrier transport in dynamic heterojunctions.Furthermore,the output voltage can be delicately adjusted and enhanced with the interface energy level engineering of inserting dielectric layers.Under the ultrahigh interface electric field,hot electrons will still transfer across the interface through the tunneling and hopping effect.In particular,the intrinsic anisotropy of black phosphorus arising from the lattice structure produces extraordinary electronic,transport,and mechanical properties exploited in our dynamic heterojunction generator.Herein,the voltage of 6.1 V,current density of 124.0 A/m^(2),power density of 201.0 W/m^(2),and energy-conversion efficiency of 31.4%have been achieved based on the dynamic black phosphorus/AlN/Si heterojunction,which can be used to directly and synchronously light up light-emitting diodes.This direct-current generator has the potential to convert ubiquitous mechanical energy into electric energy and is a promising candidate for novel portable and miniaturized power sources in the in situ energy acquisition field.展开更多
A cholesterol oxidase(COD)was hybridized with Ca^(2+),Zn^(2+),Al^(3+),Fe^(2+) and Mn^(2+).After precipitation with PO_(4)^(3-) at 4℃ for 72 h,the resulting pellets were freeze-dried.In scanning electron microscopy as...A cholesterol oxidase(COD)was hybridized with Ca^(2+),Zn^(2+),Al^(3+),Fe^(2+) and Mn^(2+).After precipitation with PO_(4)^(3-) at 4℃ for 72 h,the resulting pellets were freeze-dried.In scanning electron microscopy assays,the metal-COD complexes revealed flower-like or granular structures after hybridization.Fourier transform infrared spectroscopy assay revealed the characteristic peaks of both the enzyme and metal materials.X-ray diffraction analysis indicated that COD was encapsulated in CaHPO_(4)·2H_(2)O-,Zn_(3)(PO_(4))_(2)·4H_(2)O-,AlPO_(4-),FeP_(4-) and Mn_(3)(PO_(4))_(2)·3H_(2)O-based nanostructures,respectively.Differential scanning calorimetry assay indicated significant increases in thermo-denaturation temperatures from 60.5℃ to 167.02℃,167.02℃,137.70℃,172.85℃ and 160.99℃,respectively.Using steroid derivatives as substrates,this enzyme could convert cholesterol,pregnenolone,dehydroepiandrosterone,ergosterol,b-sitosterol and stigmasterol to related single products.Hybridization in metal-based nanostructures could significantly enhance the initial conversion ratio and reaction stability of the enzyme.In addition,substrate selectivity could be affected by various metal materials.Briefly,using Ca^(2+),Zn^(2+),Al^(3+),Fe^(2+) and Mn^(2+) as hybrid raw materials could help to encapsulate COD in related metal-enzyme nanostructures,and could help to promote the stability and tolerant properties of the enzyme,while also enhancing its catalytic characteristics.展开更多
基金This work was funded by the National Natural Science Foundation of China(Nos.51202216,51502264,and 61774135)Special Foundation of Young Professor of Zhejiang University(No.2013QNA5007)Y.Wen thanks the support from the Science and Technology Project of Jiangsu Province Special Equipment Safety Supervision and Inspection Institute(KJY2017016).
文摘Searching for light and miniaturized functional device structures for sustainable energy gathering from the environment is the focus of energy society with the development of the internet of things.The proposal of a dynamic heterojunction-based direct current generator builds up new platforms for developing in situ energy.However,the requirement of different semiconductors in dynamic heterojunction is too complex to wide applications,generating energy loss for crystal structure mismatch.Herein,dynamic homojunction generators are explored,with the same semiconductor and majority carrier type.Systematic experiments reveal that the majority of carrier directional separation originates from the breaking symmetry between carrier distribution,leading to the rebounding effect of carriers by the interfacial electric field.Strikingly,NN Si homojunction with different Fermi levels can also output the electricity with higher current density than PP/PN homojunction,attributing to higher carrier mobility.The current density is as high as 214.0 A/m^(2),and internal impedance is as low as 3.6 kΩ,matching well with the impedance of electron components.Furthermore,the N-i-N structure is explored,whose output voltage can be further improved to 1.3V in the case of the N-Si/Al2O3/N-Si structure,attributing to the enhanced interfacial barrier.This approach provides a simple and feasible way of converting low-frequency disordered mechanical motion into electricity.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51202216,51502264,and 61774135)the Special Foundation of Young Professor of Zhejiang University(Grant No.2013QNA5007).
文摘Static heterojunction-based electronic devices have been widely applied because carrier dynamic processes between semiconductors can be designed through band gap engineering.Herein,we demonstrate a tunable direct-current generator based on the dynamic heterojunction,whose mechanism is based on breaking the symmetry of drift and diffusion currents and rebounding hot carrier transport in dynamic heterojunctions.Furthermore,the output voltage can be delicately adjusted and enhanced with the interface energy level engineering of inserting dielectric layers.Under the ultrahigh interface electric field,hot electrons will still transfer across the interface through the tunneling and hopping effect.In particular,the intrinsic anisotropy of black phosphorus arising from the lattice structure produces extraordinary electronic,transport,and mechanical properties exploited in our dynamic heterojunction generator.Herein,the voltage of 6.1 V,current density of 124.0 A/m^(2),power density of 201.0 W/m^(2),and energy-conversion efficiency of 31.4%have been achieved based on the dynamic black phosphorus/AlN/Si heterojunction,which can be used to directly and synchronously light up light-emitting diodes.This direct-current generator has the potential to convert ubiquitous mechanical energy into electric energy and is a promising candidate for novel portable and miniaturized power sources in the in situ energy acquisition field.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFA0900304-300)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20160053 and BE2018055)the Priority Academic Program Development of Jiangsu Higher Education Institutions,111 Project(Grant No.111-2-06).
文摘A cholesterol oxidase(COD)was hybridized with Ca^(2+),Zn^(2+),Al^(3+),Fe^(2+) and Mn^(2+).After precipitation with PO_(4)^(3-) at 4℃ for 72 h,the resulting pellets were freeze-dried.In scanning electron microscopy assays,the metal-COD complexes revealed flower-like or granular structures after hybridization.Fourier transform infrared spectroscopy assay revealed the characteristic peaks of both the enzyme and metal materials.X-ray diffraction analysis indicated that COD was encapsulated in CaHPO_(4)·2H_(2)O-,Zn_(3)(PO_(4))_(2)·4H_(2)O-,AlPO_(4-),FeP_(4-) and Mn_(3)(PO_(4))_(2)·3H_(2)O-based nanostructures,respectively.Differential scanning calorimetry assay indicated significant increases in thermo-denaturation temperatures from 60.5℃ to 167.02℃,167.02℃,137.70℃,172.85℃ and 160.99℃,respectively.Using steroid derivatives as substrates,this enzyme could convert cholesterol,pregnenolone,dehydroepiandrosterone,ergosterol,b-sitosterol and stigmasterol to related single products.Hybridization in metal-based nanostructures could significantly enhance the initial conversion ratio and reaction stability of the enzyme.In addition,substrate selectivity could be affected by various metal materials.Briefly,using Ca^(2+),Zn^(2+),Al^(3+),Fe^(2+) and Mn^(2+) as hybrid raw materials could help to encapsulate COD in related metal-enzyme nanostructures,and could help to promote the stability and tolerant properties of the enzyme,while also enhancing its catalytic characteristics.
