Molao-motheo oa Mokhoa oa PVT Kholo ea Silicon Carbide (SiC) Crystal

Mokhoa oa PVT, oo lebitso la oona le felletseng e leng Physical Vapor Transportation, ke mokhoa o tloaelehileng oa ho holisa silicon carbide (SiC)likristale tlas'a mocheso o phahameng le khatello e phahameng. Molao-motheo oa eona oa mantlha ke ho futhumatsa phofo ea silicon carbide ho isa sublimation mochesong o kaholimo ho 2300℃ le tikolohong e nang le khatello e tlase haufi le vacuum, ho etsa khase ea karabelo e nang le likarolo tsa khase tse kang Si, Si2C, le SiC2. Ka lebaka la likhatello tse fapaneng tsa karolo ea khase tsa likarolo tsa Si le C tse entsoeng ke karabelo ea sublimation ea mohato o tiileng, karolelano ea stoichiometric ea Si/C e fapana ho latela kabo ea tšimo ea mocheso. Ka hona, hoa hlokahala ho laola kabo le lipalangoang tsa likarolo tsa mohato oa khase ho netefatsa hore li fihla maemong a itseng a kristale ka phapusing ea kholo.

Ho thibela ho kristaletsoa ha mokhahlelo oa khase o sa tsitsang hore o se ke oa etsa polycrystalline silicon carbide, likristale tsa peo ea silicon carbide li behiloe holimo ho kamore ea kholo. Tlas'a khatello ea khase-phase supersaturation, likarolo tsa mokhahlelo oa khase li tla lula holim'a kristale ea peo ho etsa likristale tse le 'ngoe tsa silicon carbide. Ts'ebetso eohle ea karabelo e etsahala ka kamoreng e koetsoeng ea kholo, moo liparamente tsohle tsa sistimi ea karabelo li kopantsoeng. Phetoho efe kapa efe maemong a kholo e tla ama botsitso ba kholo ea kristale e le 'ngoe.

Ho phaella moo, dibopeho tse fapaneng tse haufi tsa dikristale tse le nngwe tsa silicon carbide mabapi le tsela eo di shebaneng ka yona le kristale di lebisa mekgweng e fapaneng ya kgokelo ya athomo le ho kopanya, ka hona di theha mefuta e fetang 200 ya di-isomer tsa silicon carbide. Thibelo ya phetoho ya matla pakeng tsa mefuta e fapaneng ya kristale e tlase haholo, kahoo phetoho ya sebopeho sa kristale e ka etsahala haholo tsamaisong ya kgolo ya kristale e le nngwe ya PVT, e leng se fellang ka mefuta e sa tsitsang ya kristale le diphoso tse fapaneng tsa kristale. Ka hona, ho hlokahala ho sebedisa disebediswa tse ikemiseditseng tsa tlhahlobo ho lemoha sebopeho sa kristale le diphoso tse fapaneng tsa ingot ya kristale.

Ts'ebetso ea ho lokisa carbide ea silicon e na le litlhoko tse phahameng haholo, haholo-holo tse bonahatsoang likarolong tse latelang:

• Ho na le litšila tse ngata tsa tikoloho ts'ebetsong ea ho kopanya phofo ea silicon carbide, e leng se etsang hore ho be thata ho fumana phofo e hloekileng haholo. Karabelo e sa fellang pakeng tsa phofo ea silicon le phofo ea carbon e le mohloli oa karabelo e ka baka ho se leka-lekane karo-karolelano ea Si/C. Sebopeho sa kristale le boholo ba likaroloana tsa phofo ea silicon carbide ka mor'a ho kopanya li thata ho li laola.
• Tlas'a maemo a mocheso o phahameng o fetang 2300℃ le haufi le vacuum, silicon carbide e feta ts'ebetsong ea phetoho ea "solid-gas-solid" le ts'ebetso ea ho etsa likristale hape ka kamoreng e koetsoeng ea graphite. Ts'ebetso ena e na le potoloho e telele ea kholo, ho thata ho e laola, 'me e na le tšekamelo ea ho ba le liphoso tse kang li-microtubules le li-inclusions.
• Carbide ea silicon e na le mefuta e fetang 200 e fapaneng ea kristale, empa hangata tlhahiso e hloka mofuta o le mong feela oa kristale. Nakong ea ts'ebetso ea kholo, phetoho ea mofuta oa kristale e ka etsahala, e leng se fellang ka liphoso tsa ho kenyelletsa mefuta e mengata. Nakong ea ts'ebetso ea ho lokisa, ho thata ho laola mofuta o le mong o itseng oa kristale ka mokhoa o tsitsitseng, 'me mokoallo oa phetoho ea matla pakeng tsa mefuta e fapaneng ea kristale o tlase haholo, e leng se eketsang bothata ba taolo. Taolo ea liparamente le lipatlisiso tse amanang le eona nakong ena li hloka litšenyehelo tse kholo tsa R&D, e leng e 'ngoe ea mabaka a litšenyehelo tse phahameng tsa carbide ea silicon e lumellanang.