Induced structural modifications in ZnS nanowires via physical state of catalyst:Highlights of 15R crystal phase  

作　　者：Sumit Kumar Frederic Fossard Gaelle Amiri Jean-Michel Chauveau Vincent Sallet 

机构地区：[1]Groupe d'Etude de la Matiere Condensee(GEMAC),Universite Paris-Saclay,CNRS-Universite de Versailles St Quentin en Yvelines,45 avenue des Etats-Unis,Versailles 78035,France [2]Laboratoire d'Etude des Microstructures(LEM),CNRS-ONERA,Universite Paris-Saclay,29 avenue Division Leclerc,Chatillon 92322,France

出　　处：《Nano Research》2022年第1期377-385,共9页纳米研究（英文版）

摘　　要：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.

关 键 词：ll-VI semiconductors MOCVD vapor-liquid-solid(VLS) vapor-solid-solid(VSS) TEM analysis POLYTYPISM 

分 类 号：TB383[一般工业技术—材料科学与工程]