Ngo-2010, uGeim noNovoselov bawine uMklomelo kaNobel ku-physics ngomsebenzi wabo ku-graphene. Lo mklomelo ushiye umbono ojulile kubantu abaningi. Phela, akuwona wonke amathuluzi okuhlola uMklomelo kaNobel avame njengetheyiphu yokunamathela, futhi akuwona wonke amathuluzi ocwaningo anomlingo futhi kulula ukuwaqonda njenge-graphene “yekristalu enezinhlangothi ezimbili”. Umsebenzi ka-2004 unganikezwa ngo-2010, okuyinto engavamile emlandweni weMklomelo kaNobel eminyakeni yamuva.
I-Graphene uhlobo lwento equkethe ungqimba olulodwa lwama-athomu e-carbon ahlelwe eduze kwi-lattice ye-honeycomb enezinhlangothi ezimbili. Njengedayimane, i-graphite, i-fullerene, ama-carbon nanotubes kanye ne-carbon amorphous, iyinto (into elula) eyakhiwe yizinto ze-carbon. Njengoba kuboniswe esithombeni esingezansi, ama-fullerene nama-carbon nanotubes angabonakala egoqwe ngandlela-thile kusuka kungqimba olulodwa lwe-graphene, oluhlanganiswe yizingqimba eziningi ze-graphene. Ucwaningo lwethiyori mayelana nokusetshenziswa kwe-graphene ukuchaza izakhiwo zezinto ezihlukahlukene ze-carbon simple (i-graphite, ama-carbon nanotubes kanye ne-graphene) seluhlale iminyaka ecishe ibe ngu-60, kodwa ngokuvamile kukholelwa ukuthi izinto ezinjalo ezinezinhlangothi ezimbili kunzima ukuziphila zodwa, zinamathele kuphela ebusweni be-substrate enezinhlangothi ezintathu noma ngaphakathi kwezinto ezifana ne-graphite. Kwaze kwaba ngo-2004 lapho u-Andre Geim nomfundi wakhe uKonstantin Novoselov besusa ungqimba olulodwa lwe-graphene ku-graphite ngokuhlola lapho ucwaningo lwe-graphene lwathola khona intuthuko entsha.
Kokubili i-fullerene (kwesobunxele) kanye ne-carbon nanotube (phakathi) kungabhekwa njengokugoqwa ungqimba olulodwa lwe-graphene ngandlela thile, kuyilapho i-graphite (kwesokudla) ibekwe ngezingqimba eziningi ze-graphene ngokuxhumeka kwamandla e-van der Waals.
Namuhla, i-graphene ingatholakala ngezindlela eziningi, futhi izindlela ezahlukene zinezinzuzo nezinkinga zazo. UGeim noNovoselov bathole i-graphene ngendlela elula. Besebenzisa i-tape esobala etholakala ezitolo ezinkulu, bakhipha i-graphene, ishidi le-graphite elinesendlalelo esisodwa kuphela sama-athomu e-carbon obukhulu, esiqeshini se-graphite ye-pyrolytic ephezulu. Lokhu kulula, kodwa ukulawulwa akukuhle kangako, futhi i-graphene enosayizi ongaphansi kwama-micron ayi-100 (ingxenye yeshumi yemilimitha) ingatholakala kuphela, engasetshenziswa ekuhlolweni, kodwa kunzima ukuyisebenzisa ekusetshenzisweni okusebenzayo. Ukufakwa komhwamuko wamakhemikhali kungakhulisa amasampula e-graphene anosayizi wamashumi amasentimitha ebusweni bensimbi. Nakuba indawo enokuqondisa okulinganayo ingama-micron ayi-100 kuphela [3,4], ibilokhu ifanele izidingo zokukhiqiza kwezinye izinhlelo zokusebenza. Enye indlela evamile ukushisa i-silicon carbide (SIC) crystal ibe ngaphezu kuka-1100 ℃ ku-vacuum, ukuze ama-athomu e-silicon aseduze kobuso aphele, futhi ama-athomu e-carbon asele ahlelwe kabusha, angathola namasampula e-graphene anezakhiwo ezinhle.
I-Graphene iyinto entsha enezakhiwo ezihlukile: ukuqhutshwa kwayo kagesi kuhle kakhulu njengethusi, futhi ukuqhutshwa kwayo kokushisa kungcono kunanoma yiziphi izinto ezaziwayo. Ibonakala kahle kakhulu. Ingxenye encane kuphela (2.3%) yokukhanya okubonakalayo okubonakalayo okuzomuncwa yi-graphene, futhi ukukhanya okuningi kuzodlula. Iminyene kangangokuthi ngisho nama-athomu e-helium (ama-molecule amancane kakhulu egesi) awakwazi ukudlula. Lezi zakhiwo zomlingo azizuzwa ngokuqondile ku-graphite, kodwa kusuka ku-quantum mechanics. Izakhiwo zayo ezihlukile zikagesi nezokukhanya zinquma ukuthi inamathemba okusetshenziswa kabanzi.
Nakuba i-graphene ivele iminyaka engaphansi kweyishumi kuphela, ibonise ukusetshenziswa okuningi kobuchwepheshe, okuyinto engavamile kakhulu emikhakheni yefiziksi nesayensi yezinto ezibonakalayo. Kuthatha iminyaka engaphezu kweyishumi noma ngisho namashumi eminyaka ukuthi izinto ezijwayelekile zisuke elabhorethri ziye empilweni yangempela. Iyini inzuzo ye-graphene? Ake sibheke izibonelo ezimbili.
I-electrode ethambile esobala
Ezintweni eziningi zikagesi, izinto ezisebenzisa ugesi ezibonakalayo zidinga ukusetshenziswa njengama-electrode. Amawashi kagesi, ama-calculator, amathelevishini, izibonisi zekristalu eliwuketshezi, izikrini zokuthinta, amaphaneli elanga kanye namanye amadivayisi amaningi awakwazi ukushiya ukuba khona kwama-electrode abonakalayo. I-electrode evame ukubonakala ebonakalayo isebenzisa i-indium tin oxide (ITO). Ngenxa yentengo ephezulu kanye nokunikezwa okulinganiselwe kwe-indium, izinto ezibonakalayo ziyaphuka futhi aziguquguquki, futhi i-electrode idinga ukufakwa engqimbeni ephakathi ye-vacuum, futhi izindleko ziphakeme kakhulu. Sekuyisikhathi eside ososayensi bezama ukuthola indawo yayo esikhundleni sayo. Ngaphezu kwezidingo zokucaca, ukuqhuba kahle kanye nokulungiselela okulula, uma ukuguquguquka kwezinto ngokwazo kukuhle, kuzofaneleka ekwenzeni "iphepha le-elekthronikhi" noma amanye amadivayisi okubonisa agoqekayo. Ngakho-ke, ukuguquguquka nakho kuyisici esibaluleke kakhulu. I-Graphene iyinto enjalo, efaneleka kakhulu kuma-electrode abonakalayo.
Abacwaningi abavela e-Samsung nase-Chengjunguan University eNingizimu Korea bathole i-graphene enobude obuyi-diagonal obungamasentimitha angu-30 ngokufaka umhwamuko wamakhemikhali futhi bayidlulisela kwifilimu ye-polyethylene terephthalate (PET) enobukhulu obuyi-188 micron ukuze bakhiqize isikrini sokuthinta esisekelwe ku-graphene [4]. Njengoba kuboniswe esithombeni esingezansi, i-graphene ekhuliswe ku-copper foil iqale ihlanganiswe ne-thermal stripping tape (ingxenye eluhlaza okwesibhakabhaka ecacile), bese i-copper foil incibilikiswa ngendlela yamakhemikhali, bese ekugcineni i-graphene idluliselwa kwifilimu ye-PET ngokushisa.
Imishini emisha yokungenisa ugesi nge-photoelectric
I-Graphene inezakhiwo zokukhanya ezihlukile kakhulu. Nakuba kunesendlalelo esisodwa sama-athomu, ingamunca u-2.3% wokukhanya okukhishwe kulo lonke ububanzi be-wavelength kusukela ekukhanyeni okubonakalayo kuya ku-infrared. Leli nani alinalutho oluphathelene nezinye izilinganiso zezinto ze-graphene futhi linqunywa yi-quantum electrodynamics [6]. Ukukhanya okumuncwayo kuzoholela ekwakhiweni kwezithwali (ama-electron nezimbobo). Ukukhiqizwa nokuthuthwa kwezithwali ku-graphene kuhluke kakhulu kulezo ezikuma-semiconductors endabuko. Lokhu kwenza i-graphene ifaneleke kakhulu emishinini yokungenisa i-photoelectric esheshayo. Kulinganiselwa ukuthi imishini enjalo yokungenisa i-photoelectric ingasebenza ngesivinini esingu-500ghz. Uma isetshenziselwa ukudlulisa isignali, ingadlulisa ama-zero ayizigidigidi ezingu-500 noma eyodwa ngomzuzwana, futhi iqedele ukudluliselwa kokuqukethwe kwama-disc amabili e-Blu ray ngomzuzwana owodwa.
Ochwepheshe abavela kwi-IBM Thomas J. Watson Research Centre e-United States basebenzise i-graphene ukukhiqiza amadivayisi okungenisa i-photoelectric angasebenza ngemvamisa ye-10GHz [8]. Okokuqala, ama-graphene flakes alungiswa ku-substrate ye-silicon embozwe nge-silica engu-300 nm ubukhulu "ngendlela yokudabula i-tape", bese kwenziwa ama-electrode egolide e-palladium noma e-titanium ane-interval engu-1 micron kanye nobubanzi obungu-250 nm. Ngale ndlela, kutholakala idivayisi yokungenisa i-photoelectric esekelwe ku-graphene.
Umdwebo weskimu wemishini yokungenisa i-graphene photoelectric kanye nezithombe ze-scanning electron microscope (SEM) zamasampula angempela. Umugqa omfushane omnyama esithombeni uhambelana nama-micron angu-5, kanti ibanga phakathi kwemigqa yensimbi liyi-micron eyodwa.
Ngokusebenzisa izivivinyo, abacwaningi bathole ukuthi le divayisi ye-photoelectric induction yesakhiwo sensimbi se-graphene ingafinyelela imvamisa yokusebenza engu-16ghz okungenani, futhi ingasebenza ngesivinini esiphezulu ebangeni lamaza kusukela ku-300 nm (eduze kwe-ultraviolet) kuya kuma-microns ayi-6 (i-infrared), kuyilapho ishubhu yendabuko ye-photoelectric induction ingakwazi ukuphendula ekukhanyeni kwe-infrared ngobude be-wavelength obude. Imvamisa yokusebenza kwemishini ye-graphene photoelectric induction isenendawo enhle yokuthuthukisa. Ukusebenza kwayo okuphezulu kwenza ibe nohlu olubanzi lwamathemba okusetshenziswa, okuhlanganisa ukuxhumana, ukulawula kude kanye nokuqapha imvelo.
Njengezinto ezintsha ezinezakhiwo ezihlukile, ucwaningo ngokusetshenziswa kwe-graphene luvela ngokulandelana. Kunzima ngathi ukubala lapha. Esikhathini esizayo, kungase kube namashubhu omphumela wensimu enziwe nge-graphene, izinkinobho zama-molecule ezenziwe nge-graphene kanye nezitholi zama-molecule ezenziwe nge-graphene empilweni yansuku zonke… I-Graphene ephuma kancane kancane elabhorethri izokhanya empilweni yansuku zonke.
Singalindela ukuthi inani elikhulu lemikhiqizo kagesi esebenzisa i-graphene lizovela maduze nje. Cabanga ukuthi kungaba mnandi kanjani uma ama-smartphone nama-netbook ethu engagoqwa, aboshwe ezindlebeni zethu, afakwe emaphaketheni ethu, noma aboshwe ezihlakaleni zethu uma engasetshenziswa!
Isikhathi sokuthunyelwe: Mashi-09-2022