Large scale zigzag zinc blende single crystal ZnS nanowires have been successfully synthesized during a vapor phase growth process together with a small yield of straight wurtzite single crystal ZnS nanowires.AuPd all...Large scale zigzag zinc blende single crystal ZnS nanowires have been successfully synthesized during a vapor phase growth process together with a small yield of straight wurtzite single crystal ZnS nanowires.AuPd alloy nanoparticles were utilized to catalyze a vapor-solid-solid growth process of both types of ZnS nanowires,instead of the more common vapor-liquid-solid growth process.Surprisingly,the vapor-phase grown zigzag zinc blende ZnS nanowires are metastable under high-energy electron irradiation in a transmission electron microscope,with straight wurtzite nanowires being much more stable.Upon exposure to electron irradiation,a wurtzite ZnO nanoparticle layer formed on the zigzag zinc blende ZnS nanowire surface with concomitant displacement damage.Both electron inelastic scattering and surface oxidation as a result of electron-beam heating occur during this structure evolution process.When prolonged higher-voltage electron irradiation was applied,local zinc blende ZnS nanowire bodies evolved into ZnS-ZnO nanocables,and dispersed ZnS-ZnO nanoparticle networks.Random AuPd nanoparticles were observed distributed on zigzag ZnS nanowire surfaces,which might be responsible for a catalytic oxidation effect and speed up the surface oxidation-induced structure evolution.展开更多
Peculiar and unique growth mechanisms involved in semiconductor nanowires(NWs)pave the way to the achievement of new crystallographic phases and remarkable material properties,and hence,studying polytypism in semicond...Peculiar and unique growth mechanisms involved in semiconductor nanowires(NWs)pave the way to the achievement of new crystallographic phases and remarkable material properties,and hence,studying polytypism in semiconductor NWs arouses a strong interest for the next generation of electronic and photonic applications.In this context,the growth of ZnS nanowires has been investigated,as bulk ZnS compound exhibits numerous unstable polytypes at high temperatures,but their stable occurrence is highly anticipated in a nanowire due to its special quasi-dimensional shape and growth modes.In this work,the idea is to provide a change in the growth mechanism via the physical state of catalyst droplet(liquid or solid)and hence,study the induced structural modifications in ZnS nanowires.The HRTEM images of VLS(via liquid alloyed catalyst)grown ZnS NWs show periodic stacking faults,which is precisely identified as a stacking sequence of cubic or hexagonal individual planes leading to an astonishing 15R crystal polymorph.This crystallographic phase is observed for the first time in nanowires.Contrastingly,NWs grown with VSS(via solid catalyst)show crystal polytypes of zinc blende and wurtzite.We calculate and discuss the role of cohesive energies in the formation of such ZnS polytypes.Further,we present the selection rules for the crystallization of such 15R structure in NWs and discuss the involved VLS and VSS growth mechanisms leading to the formation of different crystal phases.展开更多
基金Project(2022NSFSC0193)supported by the Natural Science Foundation of Sichuan Province,ChinaProject(52104143)supported by the National Natural Science Foundation of China+2 种基金Project(GKZD010084)supported by the State Key Laboratory of Ocean Engineering(Shanghai Jiao Tong University),ChinaProject(MAETIC202201)supported by the Open Project Program of Shandong Marine Aerospace Equipment Technological Innovation Center,Ludong University,ChinaProject(GJJ2202702)supported by the Key Program of Department of Education of Jiangxi Province,China。
基金The authors are grateful for the financial support from the University of Connecticut New Faculty start-up funds,and the University of Connecticut Large Faculty Research GrantAcknowledgement is also made to the Donors of the American Chemical Society Petroleum Research Fund for partial support of this research.
文摘Large scale zigzag zinc blende single crystal ZnS nanowires have been successfully synthesized during a vapor phase growth process together with a small yield of straight wurtzite single crystal ZnS nanowires.AuPd alloy nanoparticles were utilized to catalyze a vapor-solid-solid growth process of both types of ZnS nanowires,instead of the more common vapor-liquid-solid growth process.Surprisingly,the vapor-phase grown zigzag zinc blende ZnS nanowires are metastable under high-energy electron irradiation in a transmission electron microscope,with straight wurtzite nanowires being much more stable.Upon exposure to electron irradiation,a wurtzite ZnO nanoparticle layer formed on the zigzag zinc blende ZnS nanowire surface with concomitant displacement damage.Both electron inelastic scattering and surface oxidation as a result of electron-beam heating occur during this structure evolution process.When prolonged higher-voltage electron irradiation was applied,local zinc blende ZnS nanowire bodies evolved into ZnS-ZnO nanocables,and dispersed ZnS-ZnO nanoparticle networks.Random AuPd nanoparticles were observed distributed on zigzag ZnS nanowire surfaces,which might be responsible for a catalytic oxidation effect and speed up the surface oxidation-induced structure evolution.
文摘Peculiar and unique growth mechanisms involved in semiconductor nanowires(NWs)pave the way to the achievement of new crystallographic phases and remarkable material properties,and hence,studying polytypism in semiconductor NWs arouses a strong interest for the next generation of electronic and photonic applications.In this context,the growth of ZnS nanowires has been investigated,as bulk ZnS compound exhibits numerous unstable polytypes at high temperatures,but their stable occurrence is highly anticipated in a nanowire due to its special quasi-dimensional shape and growth modes.In this work,the idea is to provide a change in the growth mechanism via the physical state of catalyst droplet(liquid or solid)and hence,study the induced structural modifications in ZnS nanowires.The HRTEM images of VLS(via liquid alloyed catalyst)grown ZnS NWs show periodic stacking faults,which is precisely identified as a stacking sequence of cubic or hexagonal individual planes leading to an astonishing 15R crystal polymorph.This crystallographic phase is observed for the first time in nanowires.Contrastingly,NWs grown with VSS(via solid catalyst)show crystal polytypes of zinc blende and wurtzite.We calculate and discuss the role of cohesive energies in the formation of such ZnS polytypes.Further,we present the selection rules for the crystallization of such 15R structure in NWs and discuss the involved VLS and VSS growth mechanisms leading to the formation of different crystal phases.
基金financially supported by the Science and Technology Commission of Shanghai Municipality(20501130200)the National Natural Science Foundation of China(51402342 and 61775201)the National Defense Technology Innovation Special Zone Project.
