“Ukuguqula imizila yemfuza ngundoqo ekutyhileni imfihlelo yendaleko. Indlela yophuhliso ukusuka kweyona nto ilula ukuya kwezona ntlobo zininzi zebhayoloji ithatha amawaka eminyaka. Kodwa yonke iminyaka elikhulu lamawaka kukho ukutsiba okubukhali phambili kwindaleko” (Charles Xavier, X-Men, 2000). Ukuba silahla zonke izinto ezingeyonyani yesayensi ekhoyo kwiicomics kunye neefilimu, ke amazwi kaNjingalwazi X ayinyaniso. Ukuphuhliswa kwento kuqhubeka ngokulinganayo ixesha elininzi, kodwa ngamanye amaxesha kukho imitsi enefuthe elikhulu kuyo yonke inkqubo. Oku akusebenzi nje kuphela ekuziphendukeleni kwezilwanyana, kodwa nakwinguquko yeteknoloji, umqhubi oyintloko wabantu, uphando lwabo kunye nokuveliswa. Namhlanje siza kuqhelana nophononongo oluthi, ngokutsho kwababhali balo, kukutsiba kwangempela kwendaleko kwi-nanotechnology. Izazinzulu ezisuka kwiYunivesithi yaseMntla-ntshona (e-USA) zakwazi njani ukwenza i-heterostructure entsha enamacala amabini, kwakutheni ukuze kukhethwe igraphene kunye ne-borophene njengesiseko, kwaye zeziphi iipropati ezinokuba nazo le nkqubo? Ingxelo yeqela lophando iya kusixelela malunga noku. Hamba.
Isiseko sophando
Silivile kaninzi igama elithi “graphene” lutshintsho lwekhabhoni enamacala amabini, oluquka umaleko weeathom zekhabhoni ezi-1. Kodwa "borofen" inqabile kakhulu. Eli gama libhekisa kwikristale enamacala amabini aquka kuphela iiathom zeboron (B). Ubunokwenzeka bokuba khona kwe-borophene kwaqala kwaqikelelwa emva kwe-90s, kodwa ekusebenzeni esi sakhiwo safunyanwa kuphela ngo-2015.
Ulwakhiwo lwe-athomu ye-borophene lubandakanya izinto ezinxantathu kunye ne-hexagonal kwaye sisiphumo sokusebenzisana phakathi kwamaziko amabini kunye neziko le-multi-center in-plane bonds, eqheleke kakhulu kwizinto ezingenayo i-electron, ezibandakanya i-boron.
*Ngamaziko amabini kunye neebhondi ezininzi sithetha iibhondi zeekhemikhali - ukusebenzisana kwee-athom ezibonisa ukuzinza kwemolekyuli okanye ikristale njengesakhiwo esisodwa. Ngokomzekelo, ibhondi ye-electron ezimbini-ezimbini zenzeke xa ii-athomu ezi-2 zabelana ngee-electron ezi-2, kunye ne-elektroni eziziko ezimbini ze-electron ezintathu ze-athomu ezi-2 kunye nee-electron ezi-3, njl.
Ukusuka kumbono womzimba, i-borophene inokuba yomelele kwaye iguquguquke ngakumbi kune-graphene. Kwakhona kukholelwa ukuba izakhiwo ze-borophene zinokuba ngumncedisi osebenzayo weebhetri, ekubeni i-borophene inomthamo othile ophezulu kunye ne-electronic conductivity ekhethekileyo kunye neempawu zokuthutha i-ion. Nangona kunjalo, okwangoku le yithiyori nje.
Ukuba into yesithathu *, i-boron ine-10 ubuncinane iallotropes*. Kwifom ye-dimensional, efanayo ipholymorphism* nayo iyajongwa.
Into encinci * ekwaziyo ukwenza imixokelelwane emithathu yomanyano, ivalency yayo ibe mithathu.
I-allotropy* - xa into enye yekhemikhali inokubonakaliswa ngendlela yezinto ezimbini okanye ngaphezulu ezilula. Ngokomzekelo, i-carbon-diamond, igraphene, igraphite, i-carbon nanotubes, njl.
Polymorphism* - ukukwazi ukubakho kwento ekhoyo kwizinto ezahlukeneyo zekristale (ukuguqulwa kwepolymorphic). Kwimeko yezinto ezilula, eli gama lifana ne-allotropy.
Ngenxa yolu hlobo lubanzi lwepolymorphism, kucetyiswa ukuba iborophene inokuba ngumgqatswa ogqwesileyo wokudala ulwakhiwo olutsha olunamacala amabini, kuba ubume bebhoron obuhlukeneyo kufuneka buphumze iimfuno zokuthelekisa iiletiyisi. Ngelishwa, lo mbandela ngaphambili wawufundwe ngokukodwa kwinqanaba lethiyori ngenxa yobunzima bokudibanisa.
Kwizinto eziqhelekileyo ze-2D ezifunyenwe kwiikristale ezinomaleko obuninzi, i-heterostructures ethe nkqo inokuqondwa kusetyenziswa ukupakishwa koomatshini. Kwelinye icala, i-heterostructures yamacala amabini-dimensional isekelwe kwi-bottom-up synthesis. I-atomically lateral heterostructures echaneke kakhulu inamandla amakhulu ekusombululeni iingxaki zolawulo lwe-heterojunction, nangona kunjalo, ngenxa ye-covalent bonding, ukuhambelana kwelathisi engafezekanga kukhokelela kunxibelelwano olubanzi noluphazamisekileyo. Ngoko ke, kukho amandla, kodwa kukho iingxaki ekuyiqondeni.
Kulo msebenzi, abaphandi bakwazi ukudibanisa i-borophene kunye ne-graphene kwi-heterostructure enye ye-dimensional. Ngaphandle kokungafani kwelathisi yecrystallographic kunye nolingano phakathi kwe-borophene kunye negraphene, ukubekwa ngokulandelelana kwekhabhoni kunye ne-boron kwi-Ag (111) substrate phantsi kwe-ultra-high vacuum (UHV) iphumela kwi-athom echaneke ngokuthe ngqo i-heterointerfaces esecaleni kunye nolungelelwaniso lwelathisi oluqikelelweyo, kunye nolungelelwaniso oluthe kratya lwelatisi. .
Ukulungiselela isifundo
Ngaphambi kokuba kufundwe i-heterostructure, kwafuneka yenziwe. Ukukhula kwegraphene kunye ne-borophene kwaqhutyelwa kwigumbi le-vacuum ephezulu kunye noxinzelelo lwe-1x10-10 millibars.
I-crystal Ag (111) substrate enye yacocwa ngemijikelo ephindaphindiweyo ye-Ar + sputtering (1 x 10-5 millibar, 800 eV, imizuzu engama-30) kunye ne-thermal annealing (550 ° C, imizuzu engama-45) ukufumana i-atom ecocekileyo kunye ne-flat Ag ( 111) ngaphezulu. .
Igraphene yakhuliswa ngumphunga we-electron wentonga yegraphite esulungekileyo (99,997%) enobubanzi obuyi-2.0 mm kwi-Ag (750) substrate efudunyezwe ukuya kuma-111 °C kumbane wokufudumeza ongu- ~ 1.6 A kunye namandla ombane akhawulezayo ayi- ~ 2 kV. , enika i-emission current ye ~ 70 mA kunye ne-carbon flux ~40 nA. Uxinzelelo kwigumbi kwakuyi-1 x 10-9 millibars.
IBorophene yakhuliswa ngomqa we-electron wentonga esulungekileyo (99,9999%) yeboron kwi-submonolayer graphene kwi-Ag (400) ifudunyezwe ukuya kuma-500-111 °C. Umsinga wombane wawuyi-~1.5 A kwaye amandla ombane akhawulezayo ayeyi-1.75 kV, enika amandla akhoyo e-~34 mA kunye ne-boron flux ye-~10 nA. Uxinzelelo kwigumbi ngexesha lokukhula kwe-borophene malunga ne-2 x 10-10 millibars.
Iziphumo zophando
Umfanekiso #1
Kumfanekiso 1A kubonisiwe STM* umfanekiso okhawulezayo wegraphene ekhulileyo, apho imimandla yegraphene ibonwa ngcono kusetyenziswa imephu dI/dV (1B), phi I и V I-tunneling yangoku kunye nokufuduswa kwesampulu, kunye d - ukuxinana.
STM* — ukuskena imakroskopu.
dI/dV iimephu zesampulu zisivumele ukuba sibone ukuxinana okuphezulu kwendawo yeemeko zegraphene xa kuthelekiswa ne-Ag(111) substrate. Ngokuhambelana nezifundo zangaphambili, umgangatho we-Ag (111) unophawu lwenyathelo, olutshintshelwe kumandla alungileyo dI/dV ispectrum yegraphene (1C), ecacisa ingxinano ephezulu yendawo yeemeko zegraphene kwi 1B kwi 0.3 eV.
Kumfanekiso 1D sinokubona ubume be-graphene yodwa, apho i-honeycomb lattice kunye moiré superstructure*.
Superstructure* - inkalo yesakhiwo se-crystalline compound ephinda ngexesha elithile kwaye ngaloo ndlela idala isakhiwo esitsha kunye nexesha elahlukileyo lokutshintsha.
Moire* -ukubekwa okuphezulu kweepateni ezimbini zemesh ze periodic ngaphezulu kwenye.
Kwiqondo lokushisa eliphantsi, ukukhula kukhokelela ekubunjweni kwe-dendritic kunye ne-graphene domains eneziphene. Ngenxa yobuthathaka bentsebenziswano phakathi kwegraphene kunye ne-substrate engaphantsi, ulungelelwaniso olujikelezayo lwegraphene ngokubhekiselele kwi-Ag engaphantsi (111) ayiyodwa.
Emva kokubekwa kwe-boron, ukuskena i-microscopy yetonela (1E) ibonise ubukho bendibaniselwano yommandla we-borophene kunye negraphene. Kwakhona kubonakala emfanekisweni yimimandla engaphakathi kwegraphene, eyathi kamva yachongwa njengegraphene edityaniswe neborophene (eboniswe emfanekisweni). Gr/B). Izinto zomgca ezijoliswe kumacala amathathu kwaye zahlulwe nge-engile ye-120 ° nazo zibonakala ngokucacileyo kule ndawo (iintolo ezimthubi).
Umfanekiso #2
Ifoto ivuliwe 2Angokunjalo 1E, qinisekisa ukubonakala kokudakumba okumnyama kwendawo kwigraphene emva kokufakwa kwe-boron.
Ukuze uphonononge ngcono olu kwakheka kunye nokufumanisa imvelaphi yazo, kwathathwa enye ifoto yale ndawo, kodwa kusetyenziswa iimephu |dlnI/dz| (2B), phi I - itonela yangoku, d kukuxinana, kwaye z - ukuhlukana kweprobe-isampulu (isithuba phakathi kwenaliti ye-microscope kunye nesampuli). Ukusetyenziswa kobu buchule kwenza kube lula ukufumana imifanekiso enesisombululo esiphezulu sendawo. Ungasebenzisa kwakhona i-CO okanye i-H2 kwinaliti ye-microscope kule nto.
Umfanekiso 2C ngumfanekiso ofunyenwe kusetyenziswa i-STM enencam yayo yayigqunywe ngeCO. Ukuthelekiswa kwemifanekiso А, В и С ibonisa ukuba zonke izinto zeathom zichazwa njengeeheksagoni ezikhanyayo ezintathu ezikufuphi eziqondiswe kumacala amabini angalinganiyo (oonxantathu obomvu nabatyheli emifanekisweni).
Imifanekiso eyandisiweyo yale ndawo (2D) qinisekisa ukuba ezi zinto zihambelana nokungcola kwe-boron dopant, ezihlala kwii-graphene sublattices ezimbini, njengoko kubonisiwe kwizakhiwo ezibekwe phezulu.
I-CO yokubeka inaliti ye-microscope yenza ukuba kube lula ukuveza ubume bejometri yephepha le-borophene (2E), okungenakwenzeka ukuba inaliti yayisemgangathweni (isinyithi) ngaphandle kokutyathwa kwe-CO.
Umfanekiso #3
Ukwenziwa kwe-heterointerfaces esecaleni phakathi kwe-borophene kunye negraphene (3A) kufuneka yenzeke xa iborophene ikhula ecaleni kwemimandla yegraphene esele ineboron.
Iingcali zenzululwazi zikhumbuza ukuba i-heterointerfaces esecaleni esekelwe kwi-graphene-hBN (i-graphene + boron nitride) ine-lattice consistency, kunye ne-heterojunctions esekelwe kwi-transition metal dichalcogenides ine-symmetry consistency. Kwimeko yegraphene / borophene, imeko yahluke kancinane - banokufana okuncinci kwesakhiwo ngokumalunga ne-lattice constants okanye i-crystal symmetry. Nangona kunjalo, ngaphandle koku, igraphene esecaleni/i-borophene heterointerface ibonisa phantse ukugqibelela kokungaguquguquki kweathom, kunye nomqolo webhoron (umqolo oMkhulu) ulungelelaniswa nezigzag (ZZ) izikhombisi zegraphene (3A). Vula 3B umfanekiso okhulisiwe wommandla we-ZZ we-heterointerface ubonisiwe (imigca eluhlaza okwesibhakabhaka ibonisa izinto ezidibeneyo ezihambelana ne-boron-carbon covalent bonds).
Ekubeni i-borophene ikhula kubushushu obuphantsi xa kuthelekiswa negraphene, imiphetho yedomeyini yegraphene ayinakwenzeka ukuba ibe nokuhamba okuphezulu xa kusenziwa i-heterointerface ene-borophene. Ke ngoko, i-heterointerface ephantse yachaneka ngeathom inokuba sisiphumo solungelelwaniso olwahlukileyo kunye neempawu zeebhondi ze-boron ezininzi. Ukuskena itonela ispectroscopy spectra (3C) kunye nokuhanjiswa kwetonela eyahlukileyo (3D) bonisa ukuba utshintsho lwe-elektroniki ukusuka kwigraphene ukuya kwi-borophene lwenzeka kumgama we ~5 Å kungekho namazwe ojongano olubonakalayo.
Kumfanekiso 3E Kubonisiwe imizobo emithathu yokuskena ye-spectroscopy ethatyathwe kwimigca emithathu edayiweyo kwi-3D, eqinisekisa ukuba olu tshintsho lufutshane lwe-elektroniki alunaluvelwano kulwakhiwo lwendawo oluphakathi kobuso kwaye luthelekiseka naleyo yojongano lwe-borophene-silver.
Umfanekiso #4
Igraphene ubudlelwane* nayo ikhe yafundwa ngokubanzi ngaphambili, kodwa ukuguqulwa kwe-intercalants ibe yinyani ye-2D sheets kunqabile.
Unxulumano* - ukubandakanywa okubuyiselwayo kwe-molecule okanye iqela leemolekyuli phakathi kwezinye iimolekyuli okanye amaqela eemolekyuli.
Iradiyasi encinci yeathom yeboron kunye nentsebenziswano ebuthathaka phakathi kwegraphene kunye ne-Ag(111) icebisa unxulumano olunokwenzeka lwegraphene neboron. Kumfanekiso 4A ubungqina buboniswa kungekuphela nje kwe-boron intercalation, kodwa kunye nokuqulunqwa kwee-heterostructures ze-borophene-graphene ezithe nkqo, ngokukodwa iindawo ezinxantathu ezijikelezwe yigraphene. Ileyithi yenqatha yobusi ebonwe kulo mmandla ongunxantathu iqinisekisa ubukho begraphene. Nangona kunjalo, le graphene ibonisa ukuxinana kweendawo ezisezantsi kwi-50 meV xa kuthelekiswa negraphene engqongileyo (4B). Xa kuthelekiswa negraphene ngokuthe ngqo kwi-Ag(111), akukho bungqina bokuxinana okuphezulu kwendawo yamazwe kwi-spectrum. dI/dV (4C, ijika eliluhlaza okwesibhakabhaka), elihambelana ne-Ag (111) yesimo somphezulu, bubungqina bokuqala be-boron intercalation.
Kwakhona, njengoko kulindelekile kuthungelwano oluyinxenye, i-graphene lattice ihlala iqhubekayo kulo lonke ujongano olusecaleni phakathi kwegraphene kunye nommandla ongunxantathu (4D - ihambelana nendawo yoxande kwi 4A, isangqa kumgca wamachokoza obomvu). Umfanekiso osebenzisa i-CO kwinaliti ye-microscope uqinisekisile ubukho be-boron substitution ukungcola (4E - ihambelana nendawo yoxande kwi 4A, isangqa kumgca onamanqaku atyheli).
Iinaliti zeMicroscope ngaphandle kwengubo nazo zisetyenziswe ngexesha lokuhlalutya. Kule meko, iimpawu zomgca wecala elinye kunye ne periodicity ye-5 Å ziye zatyhilwa kwiinkalo zegraphene ezidibeneyo (4F и 4G). Ezi zakhiwo ezinomlinganiselo omnye zifana nemiqolo ye-boron kwimodeli ye-borophene. Ukongeza kwiseti yamanqaku ahambelana negraphene, iFourier iguqula umfanekiso ibe 4G Ubonisa ipere yamanqaku e-orthogonal ahambelana no-3 Å x 5 Å iletisi yoxande (4H), evumelana kakhulu nemodeli ye-borophene. Ukongeza, ulungelelwaniso oluphindwe kathathu olujongweyo lweziqalelo zomgca (1E) ivumelana kakuhle nesakhiwo esifanayo esiphambili esijongwe kumaphepha e-borophene.
Lonke olu qwalaselo lucebisa ngamandla uthungelwano lwegraphene nge-borophene kufutshane nemiphetho ye-Ag, nto leyo ekhokelela ekwenziweni kwe-heterostructures ye-borophene–graphene ethe nkqo, enokuthi iphunyezwe kakuhle ngokunyusa ukugqunywa kokuqala kwegraphene.
4I luphawu lweskim seheterostructure ethe nkqo kwi 4H, apho isalathiso somqolo we-boron (utolo olupinki) lulungelelaniswe ngokusondeleyo ne-zigzag yecala legraphene (utolo olumnyama), ngaloo ndlela lwenza i-heterostructure ejikelezayo ethe nkqo.
Ukuze ufumane ulwazi oluthe kratya malunga nee-nuances zophononongo, ndincoma ukujonga и kuye.
Ipilo
Olu phononongo lubonise ukuba i-borophene iyakwazi ukwenza i-heterostructures esecaleni nethe nkqo ngegraphene. Iinkqubo ezinjalo zingasetyenziselwa ukuphuhliswa kweentlobo ezintsha zezinto ezimbini-dimensional ezisetyenziswa kwi-nanotechnology, i-flexible and wearable electronics, kunye neentlobo ezintsha ze-semiconductors.
Abaphandi ngokwabo bakholelwa ukuba uphuhliso lwabo lunokuba lutyhalela phambili olunamandla kwiitekhnoloji ezinxulumene ne-elektroniki. Nangona kunjalo, kusenzima ukutsho ngokuqinisekileyo ukuba amazwi abo aya kuba sisiprofeto. Okwangoku, kuninzi ekufuneka kuphandwe, kuqondwe kwaye kuyilwe ukuze ezo ngcamango zenzululwazi zizalise iingqondo zenzululwazi zibe yinyani epheleleyo.
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