基于第一性原理的低維納米ZnO結(jié)構(gòu)的模擬研究.pdf

1、獨(dú)創(chuàng)性聲明本人聲明所呈交的論文是我個(gè)人在導(dǎo)師指導(dǎo)下進(jìn)行的研究工作及取得的研究成果。盡我所知，除了文中特別加以標(biāo)注和致謝的地方外，論文中不包含其他人已經(jīng)發(fā)表或撰寫(xiě)過(guò)的研究成果，也不包含為獲得寧夏大學(xué)或其它教育機(jī)構(gòu)的學(xué)位或證書(shū)而使用過(guò)的材料。與我一同工作的同志對(duì)本研究所做的任何貢獻(xiàn)均已在論文中作了明確的說(shuō)明并表示了謝意。研究生簽名：劾幺兩時(shí)間：2D仔年芻月21日關(guān)于論文使用授權(quán)的說(shuō)明本人完全了解寧夏大學(xué)有關(guān)保留、使用學(xué)位論文的規(guī)定，即：學(xué)校

2、有權(quán)保留送交論文的復(fù)印件和磁盤(pán)，允許論文被查閱和借閱，可以采用影印、縮印或掃描等復(fù)制手段保存、匯編學(xué)位論文。同意寧夏大學(xué)可以用不同方式在不同媒體上發(fā)表、傳播學(xué)位論文的全部或部分內(nèi)容。(保密的學(xué)位論文在解密后應(yīng)遵守此協(xié)議)時(shí)問(wèn)：2pf弓年芻月27日時(shí)間：2D，3年S月27日捅坳撕擬：c、，1名：簽名生簽究師研導(dǎo)AbstractZincoxide(ZnO)isadirectwidebandgap(Eg=337eV)semiconductor

3、ofIIVIgroup，withahighexcitonbindingenergy(≈60meV)atroomtemperatureComparedwithGaN，ithasmanysimilaritiesinthecrystallancecharacteristics，thebandstructureandthephotoelectricpropertiesMoreover，italsohashigherexcitonbindinge

4、nergyandthelowgrowthtemperatureTherefore，itwasconsideredtobeanewkindofshortwavelengthphotoelectricmaterialasGaNOntheotherhand，withtherapiddevelopmentofDensityFunctionalTheory(DFT)andrelevantnumericalalgorithmsinrecentyea

5、rs，theFirstPrinciplescalculationsbasedontheDFrhavebecometheessentialresearchtoolsforcondensedmatterphysics，quantumchemistryandmaterialsscienceInthisthesis，F(xiàn)irst—PrinciplescalculationsbasedonDFTaresystematicallyperformedt

6、ostudythevariousgroundstatepropertiesofthreedimensionalbull(ZnO，twodimensionalZnOnamofilms，onedimensionalZnOnanowiresandzerodimensionalZnOnonoclusters111emaincontentsareasfollows：(1)TheelectronicstructureofthebulkZnOwass

7、tudied，throughtheanalysisofthebandstructure，thetotaldensityofstatesandpartialdensityofstates(PDOS)，weknowthatZnOisadirectwidebandgapsemiconductorPDOSshowthatZn3dandO2pstates(especiallytheformer)playadecisiveroleinitselec

8、tronicstructureInthispart，wealsomakesomediscussionsontheselectioncriteriaofthekeyparametersused(2)CalculatestheenergybandstructureandthedensityofstatesofonedimensionalZnOnanofilms，wefoundthatpresentobviousmetallicityFort

9、henanofilmswithlessthan6ZnOdoublelayers，theireffectiveelasticconstantsaremuchlowerthanthecorrespondingbulkvalueWhilethefilmthicknesscontinuesincreasing，theobtainedresultbecomesalmostinvariableandapproachestothebuIkvalue(

10、3)SizedependentpiezoelectricityofZnOnanowireswascalculatedinCaxisBoththestructurereconstructionandquantumconfmementinZnOnanowireareconsideredtobethemaincontributionstothissizeeffectEnergybandscalculationsshowthatwithincr

11、easingdiameter，thebandgapoftheZnOnanowiresdecreasesfrom1942eVto142leV(4)ThroughstructuraloptimizationsandenergylevelsanalysisonzerodimensionalZnOnanoclusterswimhexagonalprismconfigurationswefoundthatthestructuralrelaxati

12、onsledtozincatomsmovingtowardthecenterofthecluster，whereasoxygenatomsmovingoutwardThisisimportanttoknowwhenattemptingtopassivatedanglingbondsatthesurfaceswithsurfactants，sincetheywillthenbebondedfirstofalltooxygenatomsKe