Mu 2010, Geim ndi Novoselov adapambana Mphoto ya Nobel mu fizikisi chifukwa cha ntchito yawo pa graphene. Mphoto iyi yasiya chidwi chachikulu kwa anthu ambiri. Kupatula apo, si chida chilichonse choyesera cha Mphoto ya Nobel chomwe chili chofala ngati tepi yomatira, ndipo si chinthu chilichonse chofufuzira chomwe chili chamatsenga komanso chosavuta kumva ngati graphene ya "magalasi awiri". Ntchitoyi mu 2004 ikhoza kuperekedwa mu 2010, zomwe sizipezeka kawirikawiri m'mbiri ya Mphoto ya Nobel m'zaka zaposachedwa.
Graphene ndi mtundu wa chinthu chomwe chimakhala ndi gawo limodzi la maatomu a kaboni lomwe limakonzedwa bwino kwambiri kukhala lattice ya uchi wa magawo awiri. Monga diamondi, graphite, fullerene, machubu a kaboni ndi kaboni wopanda mawonekedwe, ndi chinthu (chinthu chosavuta) chopangidwa ndi zinthu za kaboni. Monga momwe chithunzi chili pansipa chikusonyezera, machubu a fullerene ndi machubu a kaboni amatha kuwoneka ngati akukulungidwa mwanjira ina kuchokera ku gawo limodzi la graphene, lomwe limayikidwa ndi zigawo zambiri za graphene. Kafukufuku wokhudzana ndi kugwiritsa ntchito graphene pofotokoza makhalidwe a zinthu zosiyanasiyana zosavuta za kaboni (graphite, machubu a kaboni ndi graphene) wakhalapo kwa zaka pafupifupi 60, koma nthawi zambiri amakhulupirira kuti zinthu ziwirizi zimakhala zovuta kukhalapo zokha, zimangolumikizidwa pamwamba pa gawo la magawo atatu kapena mkati mwa zinthu monga graphite. Mpaka mu 2004, Andre Geim ndi wophunzira wake Konstantin Novoselov adachotsa gawo limodzi la graphene kuchokera ku graphite kudzera mu zoyeserera pomwe kafukufuku wa graphene adapeza chitukuko chatsopano.
Zonse ziwiri za fullerene (kumanzere) ndi carbon nanotube (pakati) zitha kuonedwa ngati zikukulungidwa ndi gawo limodzi la graphene mwanjira ina, pomwe graphite (kumanja) imayikidwa ndi zigawo zingapo za graphene kudzera mu kulumikizana kwa mphamvu ya van der Waals.
Masiku ano, graphene ingapezeke m'njira zambiri, ndipo njira zosiyanasiyana zili ndi ubwino ndi kuipa kwake. Geim ndi Novoselov adapeza graphene m'njira yosavuta. Pogwiritsa ntchito tepi yowonekera yomwe imapezeka m'masitolo akuluakulu, adachotsa graphene, pepala la graphite lokhala ndi gawo limodzi lokha la maatomu a kaboni, kuchokera ku chidutswa cha pyrolytic graphite yapamwamba kwambiri. Izi ndizosavuta, koma kulamulira sikwabwino kwenikweni, ndipo graphene yokhala ndi kukula kosakwana ma microns 100 (gawo limodzi mwa magawo khumi a millimeter) ingapezeke kokha, yomwe ingagwiritsidwe ntchito poyesa, koma ndizovuta kugwiritsidwa ntchito pochita ntchito. Kuyika kwa nthunzi ya mankhwala kumatha kukulitsa zitsanzo za graphene zokhala ndi kukula kwa masentimita makumi pamwamba pa chitsulo. Ngakhale kuti dera lomwe lili ndi mawonekedwe okhazikika ndi ma microns 100 okha [3,4], lakhala loyenera pazosowa zopangira za ntchito zina. Njira ina yodziwika bwino ndikutentha kristalo wa silicon carbide (SIC) mpaka madigiri opitilira 1100 ℃ mu vacuum, kuti maatomu a silicon omwe ali pafupi ndi pamwamba asungunuke, ndipo maatomu otsala a carbon akonzedwenso, omwe angapezenso zitsanzo za graphene zokhala ndi makhalidwe abwino.
Graphene ndi chinthu chatsopano chokhala ndi makhalidwe apadera: mphamvu yake yoyendetsera magetsi ndi yabwino kwambiri ngati mkuwa, ndipo mphamvu yake yoyendetsera kutentha ndi yabwino kuposa chinthu chilichonse chodziwika. Ndi yowonekera bwino kwambiri. Gawo laling'ono lokha (2.3%) la kuwala kowoneka bwino komwe kumayendetsedwa ndi graphene lidzayamwa, ndipo kuwala kwakukulu kudzadutsa. Ndi lolemera kwambiri kotero kuti ngakhale maatomu a helium (mamolekyu ang'onoang'ono a mpweya) sangadutse. Makhalidwe amatsenga awa sachokera mwachindunji ku graphite, koma kuchokera ku quantum mechanics. Makhalidwe ake apadera amagetsi ndi kuwala amatsimikizira kuti ali ndi mwayi wogwiritsidwa ntchito kwambiri.
Ngakhale kuti graphene yangowonekera kwa zaka zosakwana khumi zokha, yawonetsa ntchito zambiri zaukadaulo, zomwe sizichitika kawirikawiri m'magawo a sayansi ya sayansi ndi zinthu zakuthupi. Zimatenga zaka zoposa khumi kapena makumi ambiri kuti zinthu wamba zisinthe kuchoka ku labotale kupita ku moyo weniweni. Kodi ntchito ya graphene ndi yotani? Tiyeni tiwone zitsanzo ziwiri.
Maelekitirodi ofewa owonekera
Mu zida zambiri zamagetsi, zinthu zowongolera zowonekera bwino ziyenera kugwiritsidwa ntchito ngati ma electrode. Mawotchi amagetsi, ma calculator, ma TV, ma display amadzimadzi a crystal, ma touch screen, ma solar panels ndi zida zina zambiri sizingasiye kukhalapo kwa ma electrode owonekera. Ma electrode owonekera bwino achikhalidwe amagwiritsa ntchito indium tin oxide (ITO). Chifukwa cha mtengo wokwera komanso kupezeka kochepa kwa indium, zinthuzo zimakhala zofooka komanso zopanda kusinthasintha, ndipo ma electrode amafunika kuyikidwa pakati pa vacuum, ndipo mtengo wake ndi wokwera. Kwa nthawi yayitali, asayansi akhala akuyesera kupeza cholowa chake. Kuphatikiza pa zofunikira za kuwonekera bwino, kuyendetsa bwino komanso kukonzekera kosavuta, ngati kusinthasintha kwa zinthuzo kuli bwino, zidzakhala zoyenera kupanga "pepala lamagetsi" kapena zida zina zowonetsera zopindika. Chifukwa chake, kusinthasintha nakonso ndi gawo lofunika kwambiri. Graphene ndi chinthu choterocho, chomwe chimayenera kwambiri ma electrode owonekera.
Ofufuza ochokera ku Samsung ndi chengjuguan University ku South Korea adapeza graphene yotalika mainchesi 30 ndi mankhwala otulutsa nthunzi ndipo adaisamutsira ku filimu ya polyethylene terephthalate (PET) ya mainchesi 188 kuti apange chophimba chokhudza chochokera ku graphene [4]. Monga momwe zasonyezedwera pachithunzi pansipa, graphene yomwe imamera pa pepala la mkuwa imalumikizidwa koyamba ndi tepi yotenthetsera (gawo labuluu lowonekera), kenako pepala la mkuwa limasungunuka pogwiritsa ntchito njira ya mankhwala, ndipo pamapeto pake graphene imasamutsidwa ku filimu ya PET potenthetsera.
Zipangizo zatsopano zoyatsira magetsi pogwiritsa ntchito photoelectric
Graphene ili ndi mawonekedwe apadera kwambiri. Ngakhale kuti pali gawo limodzi lokha la maatomu, imatha kuyamwa 2.3% ya kuwala komwe kumatulutsidwa mu utali wonse wa wavelength kuyambira kuwala kowoneka mpaka infrared. Chiwerengerochi sichikugwirizana ndi magawo ena a graphene ndipo chimatsimikiziridwa ndi quantum electrodynamics [6]. Kuwala komwe kumayamwa kudzatsogolera ku kupanga zonyamulira (ma electron ndi mabowo). Kupanga ndi kunyamula zonyamulira mu graphene ndizosiyana kwambiri ndi zomwe zili mu semiconductors zachikhalidwe. Izi zimapangitsa graphene kukhala yoyenera kwambiri pazida zoyatsira zamagetsi zofulumira kwambiri. Akuti zida zoyatsira zamagetsi zoterezi zitha kugwira ntchito pafupipafupi ya 500ghz. Ngati zigwiritsidwa ntchito potumiza chizindikiro, zimatha kutumiza ziro 500 biliyoni kapena amodzi pa sekondi imodzi, ndikumaliza kutumiza zomwe zili mu ma disc awiri a Blu ray mu sekondi imodzi.
Akatswiri ochokera ku IBM Thomas J. Watson Research Centre ku United States agwiritsa ntchito graphene kupanga zipangizo zolowetsa magetsi zomwe zingagwire ntchito pa 10GHz frequency [8]. Choyamba, ma graphene flakes anakonzedwa pa silicon substrate yokutidwa ndi silica yokhuthala ya 300 nm pogwiritsa ntchito "tepi yong'amba", kenako ma electrode agolide a palladium kapena titanium okhala ndi interval ya 1 micron ndi m'lifupi mwa 250 nm anapangidwa pamenepo. Mwanjira imeneyi, chipangizo cholowetsa magetsi chochokera ku graphene chimapezeka.
Chithunzi chojambulidwa cha zida zowunikira za graphene photoelectric ndi scanning electron microscope (SEM) za zitsanzo zenizeni. Mzere wakuda waufupi pachithunzichi ukufanana ndi ma microns 5, ndipo mtunda pakati pa mizere yachitsulo ndi micron imodzi.
Kudzera mu zoyeserera, ofufuza adapeza kuti chipangizochi chachitsulo cha graphene chomwe chimagwiritsa ntchito kuwala kwa photoelectric chimatha kufika pa 16ghz pafupipafupi, ndipo chimagwira ntchito mwachangu kwambiri kuyambira 300 nm (pafupi ndi ultraviolet) mpaka 6 microns (infrared), pomwe chubu chachikhalidwe cha photoelectric induction sichingayankhe kuwala kwa infrared ndi kutalika kwa ultraviolet. Kuchuluka kwa ntchito kwa zida za graphene photoelectric induction kudakali ndi malo abwino oti ziwongolere. Kugwira ntchito kwake kwapamwamba kumapangitsa kuti ikhale ndi mwayi wogwiritsa ntchito zinthu zosiyanasiyana, kuphatikizapo kulumikizana, kuyendetsa kutali komanso kuyang'anira chilengedwe.
Monga chinthu chatsopano chokhala ndi makhalidwe apadera, kafukufuku wokhudza kugwiritsa ntchito graphene akubwera limodzi pambuyo pa lina. N'zovuta kuti tiwawerenge apa. M'tsogolomu, pakhoza kukhala machubu opangidwa ndi graphene, ma switch a molecular opangidwa ndi graphene ndi ma molecular detector opangidwa ndi graphene m'moyo watsiku ndi tsiku… Graphene yomwe imatuluka pang'onopang'ono mu labotale idzawala m'moyo watsiku ndi tsiku.
Titha kuyembekezera kuti zinthu zambiri zamagetsi zomwe zimagwiritsa ntchito graphene zidzawonekera posachedwa. Taganizirani momwe zingakhalire zosangalatsa ngati mafoni athu ndi ma netbooks angakulungidwe, kumangidwa m'makutu mwathu, kulowetsedwa m'matumba mwathu, kapena kuzunguliridwa m'manja mwathu pamene sitikugwiritsa ntchito!
Nthawi yotumizira: Marichi-09-2022