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
There is a rising prospective in harvesting energy from the environment,as in situ energy is required for the distributed sensors in the interconnected information society,among which the water flow energy is the most...There is a rising prospective in harvesting energy from the environment,as in situ energy is required for the distributed sensors in the interconnected information society,among which the water flow energy is the most potential candidate as a clean and abundant mechanical source.However,for microscale and unordered movement of water,achieving a sustainable direct-current generating device with high output to drive the load element is still challenging,which requires for further exploration.Herein,we propose a dynamic PN water junction generator with moving water sandwiched between two semiconductors,which outputs a sustainable direct-current voltage of 0.3 V and a current of 0.64μA.The mechanism can be attributed to the dynamic polarization process of water as moving dielectric medium in the dynamic PN water junction,under the Fermi level difference of two semiconductors.We further demonstrate an encapsulated portable power-generating device with simple structure and continuous direct-current voltage output of 0.11 V,which exhibits its promising potential application in the field of wearable devices and the IoTs.展开更多
SiO-based materials represent a promising class of anodes for lithium-ion batteries(LIBs),with a high theoretical capacity and appropriate and safe Li-insertion potential.However,SiO experiences a large volume change ...SiO-based materials represent a promising class of anodes for lithium-ion batteries(LIBs),with a high theoretical capacity and appropriate and safe Li-insertion potential.However,SiO experiences a large volume change during the electrochemical reaction,low Li diffusivity,and low electron conductivity,resulting in degradation and low rate capability for LIBs.Here,we report on the rapid crafting of SiO–Sn_(2)Fe@C composites via a one-step plasma milling process,leading to an alloy of Sn and Fe and in turn refining SiO and Sn_(2)Fe into nanoparticles that are well dispersed in a nanosized,few-layer graphene matrix.The Sn and Fe nanoparticles generated during the first Li-insertion process form a stable network to improve Li diffusivity and electron conductivity.As an anode mate-rial,the SiO–Sn_(2)Fe@C composite manifests high reversible capacities,superior cycling stability,and excellent rate capability.The capacity retention is found to be as high as 95%and 84%at the 100th and 300th cycles under 0.3 C.During rate capability testing at 3,6,and 11 C,the capacity retentions are 71%,60%,and 50%,respectively.This study highlights that this simple,one-step plasma milling strategy can further improve SiO-based anode materials for high-performance LIBs.展开更多
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S.S.Lin thanks the support from the National Natural Science Foundation of China(No.51202216,51502264,61774135)K.H.Liu thanks the support from the Beijing Natural Science Foundation(JQ19004)+4 种基金Beijing Excellent Talents Training Support(2017000026833ZK11)Bureau of Industry and Information Technology of Shenzhen(No.201901161512)Key-Area Research and Development Program of Guangdong Province(Grant Nos.2019B010931001,2020B010189001)Project funded by the China Postdoctoral Science Foundation(2019M660001)Postdoctoral Innovative Personnel Support Program(BX20180013).
文摘There is a rising prospective in harvesting energy from the environment,as in situ energy is required for the distributed sensors in the interconnected information society,among which the water flow energy is the most potential candidate as a clean and abundant mechanical source.However,for microscale and unordered movement of water,achieving a sustainable direct-current generating device with high output to drive the load element is still challenging,which requires for further exploration.Herein,we propose a dynamic PN water junction generator with moving water sandwiched between two semiconductors,which outputs a sustainable direct-current voltage of 0.3 V and a current of 0.64μA.The mechanism can be attributed to the dynamic polarization process of water as moving dielectric medium in the dynamic PN water junction,under the Fermi level difference of two semiconductors.We further demonstrate an encapsulated portable power-generating device with simple structure and continuous direct-current voltage output of 0.11 V,which exhibits its promising potential application in the field of wearable devices and the IoTs.
基金This work was supported by the National Natural Science Foundation of China(grant numbers 52001124,52071144,51831009,and 51621001).
文摘SiO-based materials represent a promising class of anodes for lithium-ion batteries(LIBs),with a high theoretical capacity and appropriate and safe Li-insertion potential.However,SiO experiences a large volume change during the electrochemical reaction,low Li diffusivity,and low electron conductivity,resulting in degradation and low rate capability for LIBs.Here,we report on the rapid crafting of SiO–Sn_(2)Fe@C composites via a one-step plasma milling process,leading to an alloy of Sn and Fe and in turn refining SiO and Sn_(2)Fe into nanoparticles that are well dispersed in a nanosized,few-layer graphene matrix.The Sn and Fe nanoparticles generated during the first Li-insertion process form a stable network to improve Li diffusivity and electron conductivity.As an anode mate-rial,the SiO–Sn_(2)Fe@C composite manifests high reversible capacities,superior cycling stability,and excellent rate capability.The capacity retention is found to be as high as 95%and 84%at the 100th and 300th cycles under 0.3 C.During rate capability testing at 3,6,and 11 C,the capacity retentions are 71%,60%,and 50%,respectively.This study highlights that this simple,one-step plasma milling strategy can further improve SiO-based anode materials for high-performance LIBs.
