新型孔状石墨烯及其纳米带电性和输运性质的理论分析-theoretical analysis of novel porous graphene and its nano - charged and transport properties.docx

新型孔状石墨烯及其纳米带电性和输运性质的理论研究摘要新型孔状石墨烯，是一类有周期性孔的大π键共轭体系，它具有类似蜂窝状的二维结构。这种新型的孔状石墨烯与纯石墨烯的能带结构相比，表现出完全不同的半导体性质，可应用于众多领域，如光催化载体、储氢材料、纳米电子材料等。源于新型孔状石墨烯奇特的几何构型及电子结构，本文基于第一性原理的密度泛函理论和非平衡格林函数方法，构造二维碳氢孔状石墨烯n-Benzo-CMPs(n=3,4,5)及其硼氮共掺杂衍生物BN-n-Benzo-CMPs(n=3,4,5)以及一维孔状石墨烯纳米带，计算电性和输运性质。对电性质的研究表明所有的二维碳氢孔状石墨烯和硼氮共掺杂孔状石墨烯都是在Г点具有直接带隙的半导体，带隙范围为0.57~1.75eV。它们都具有纳米级孔，孔径范围为0.368~1.293nm。能带带隙随着孔径增大而减小。硼氮掺杂也使能带带隙减小。所有的一维孔状石墨纳米带都是具有直接带隙的半导体，带隙范围为0.11~2.00eV。对于一维孔状石墨纳米带，无论是扶手椅型还是锯齿型纳米带，孔径n增大和硼氮掺杂都可使能带带隙减小，同时宽度也对能带带隙有影响。对输运性质的研究发现两极体系BN-3-Benzo-CMP比3-Benzo-CMP具有更强的电流响应、更强的传输峰，表现出更强的导电特性。在所有的一维孔状石墨烯纳米带中，两极体系BN-3ZGNR(W=4)表现出最强的电流响应和传输峰，与两极体系BN-3-Benzo-CMP具有相似的导电性能，都将成为潜在的低维纳米电子器件材料。关键词孔状石墨烯；纳米带；半导体；电性质；输运性质TheoreticalStudyforElectronicandTransportPropertiesofNovelPorousGraphenesandCorrespondingPorousGrapheneNanoribbonsAbstractThenovelporousgraphenesisaclassoftwo-dimensionalhoneycombstructureswithperiodicporousandlargeπ-conjugatesystem.Comparingwiththebandstructureofpuregraphene,theporousgraphenesshowsemiconductorproperties,whichcanbeappliedinmanyfields,suchaslightcatalyticcarriers,hydrogenstoragematerials,nanoelectronicmaterials,etc.Owingtothepeculiargeometricalandelectronicstructuresofporousgraphenes,weconstructandinvestigatetheelectronicandelectrontransportpropertiesofaseriesoftwo-dimensionalhydrocarbonporousn-Benzo-CMPs(n=3,4,5)sheetsandtheirBNcodopedderivatives,BN-n-Benzo-CMPsusingdensity-functionaltheory(DFT)calculationsandthenon-equilibriumGreensfunction(NEGF),aswellasone-dimensional(1D)porousgraphenenanoribbons.Thestudyofelectronicpropertiesshowthatallofthetwo-dimensionalhydrocarbonporousgraphenesandBNcodopedderivativesaresemiconductorswithdirectbandgaps(0.57-1.75eV)inГpoint.Theypossessnanoscalepores,andtheporesizevariesfrom0.368to1.293nm.Thebandgapsdecreasewiththeporesizeenlarging.TheBNdopedcandecreasethebandgap,too.Alloftheone-dimensionalporousgraphenenanoribbonsarealsosemiconductorswithdirectbandgaps(0.11~2.00eV)atГpoint.Forone-dimensionalporousgraphenenanoribbons,eitherarmchair-nanoribbon