Ceramic semiconductor katundu

Mawonekedwe:

The resistivity ya ceramics okhala ndi semiconductor properties ndi pafupifupi 10-5~ 107ω.cm, ndipo semiconductor katundu wa ceramic zipangizo akhoza kupezedwa ndi doping kapena kuchititsa lattice kupunduka chifukwa stoichiometric kupatuka. Ma Ceramics omwe amagwiritsa ntchito njirayi akuphatikizapo TiO2,

ZnO, CdS, BaTiO3, Fe2O3, Cr2O3 ndi SiC. Makhalidwe osiyanasiyana aSemiconductor ceramicsndi kuti madulidwe awo amagetsi amasintha ndi chilengedwe, omwe angagwiritsidwe ntchito kupanga mitundu yosiyanasiyana ya zida za ceramic.

Monga kutentha tcheru, mpweya tcheru, chinyezi tcheru, kupanikizika, kuwala tcheru ndi masensa ena. Zipangizo za semiconductor spinel, monga Fe3O4, zimasakanizidwa ndi zinthu zopanda conductor spinel, monga MgAl2O4, muzitsulo zolimba zoyendetsedwa.

MgCr2O4, ndi Zr2TiO4, angagwiritsidwe ntchito ngati thermistors, amene mosamala ankalamulira kukana zipangizo zosiyanasiyana ndi kutentha. ZnO ikhoza kusinthidwa powonjezera ma oxides monga Bi, Mn, Co ndi Cr.

Ambiri mwa oxides izi si zolimba kusungunuka mu ZnO, koma kupatuka pa malire a tirigu kupanga chotchinga wosanjikiza, kuti apeze ZnO varistor ceramic zipangizo, ndipo ndi mtundu wa zinthu ndi ntchito yabwino mu varistor ceramics.

SiC doping (monga munthu wakuda wakuda, ufa wa graphite) akhoza kukonzekerazida za semiconductorndi kukhazikika kwa kutentha kwambiri, komwe kumagwiritsidwa ntchito ngati zinthu zosiyanasiyana zokakamira zotenthetsera, ndiko kuti, ndodo za silicon carbon m'ng'anjo zamagetsi zotentha kwambiri. Yang'anirani zotsutsana ndi gawo la SiC kuti mukwaniritse chilichonse chomwe mukufuna

Zomwe zimagwirira ntchito (mpaka 1500 ° C), kukulitsa mphamvu zake ndikuchepetsa gawo lazotenthetsera kumawonjezera kutentha komwe kumapangidwa. Silicon mpweya ndodo mu mpweya zidzachitika makutidwe ndi okosijeni anachita, ntchito kutentha zambiri okha 1600 ° C pansipa, mtundu wamba pakachitsulo mpweya ndodo.

Kutentha kotetezeka kogwira ntchito ndi 1350 ° C. Mu SiC, atomu ya Si imalowetsedwa ndi atomu ya N, chifukwa N ili ndi ma electron ambiri, pali ma electron owonjezera, ndipo mphamvu yake imakhala pafupi ndi gulu lapansi la conduction ndipo n'zosavuta kukweza ku gulu la conduction, kotero mphamvu iyi ya mphamvu. imatchedwanso donor level, theka ili

Ma kondakitala ndi ma semiconductors amtundu wa N kapena ma semiconductors opanga pakompyuta. Ngati atomu ya Al imagwiritsidwa ntchito mu SiC kuti ilowe m'malo mwa atomu ya Si, chifukwa cha kusowa kwa electron, mphamvu yopangidwa ndi zinthu yomwe ili pafupi ndi gulu la valence electron pamwamba, n'zosavuta kuvomereza ma electron, choncho amatchedwa kuvomereza.

Mulingo waukulu wa mphamvu, womwe umasiya malo opanda munthu mu gulu la valence lomwe lingathe kuyendetsa ma elekitironi chifukwa malo opanda kanthu amachita chimodzimodzi monga chonyamulira chabwino, amatchedwa P-mtundu semiconductor kapena hole semiconductor (H. Sarman,1989).