Highly ordered catalyst-free InGaN/GaN core-shell architecture arrays with expanded active area region

Abstract

Highly ordered,position-controlledgalliumnitride(GaN)nanowirebasedmultiple-quantum- wells (MQWs)core–shell architecturearraysaresynthesizedbymetalorganicchemicalvapor deposition (MOCVD).WeinvestigatethepossibilityofusingGaNnanowirearraysasabasal template forthegrowthofInxGa1xN/GaN MQWs.TheMQWsonthreedifferentcrystalfacets (c-, m-, and semipolar-plane) ofGaNnanowireexhibitdissimilarstructuralproperties.The structural characteristicsofInGaN/GaNcore–shell arraysareinspectedbycross-sectionalhigh- resolution transmissionelectronmicroscopy(HR-TEM).Wealsoinvestigatetheopticalproper- ties ofMQWcore–shell structurenanoarrays.TheluminescentcharacteristicsofInGaN/GaN core–shell structurearraysaredeterminedbyphotoluminescence(PL)andcathodolumines- cence (CL)measurements.ThemonochromaticCLimagesclearlyshowthelightemission behavior ofInGaN/GaNMQWcoaxialstructure.Twodistinguishablelightemissionpeakswere observed intheGaNnanowirebasedcore–shell structure.Thecharacteristicoflightemission mainly dependsonthepropertiesofMQWs,whicharegeneratedfromdifferentcrystalfacetsof GaN. Inaddition,thelightemissionintensityshowsdifferentbehaviorsdependingonthearea of theGaNnanowire m-plane. TheresultsofthisstudysuggestthatGaNnanowirearrayscanbe used asagoodalternativebasaltemplatefornext-generationlight-emittingdiodes(LEDs).