Piv txwv ntawm semiconductors. Hom, zog, tswv yim daim ntawv sau npe

Lub nto moo tshaj plaws yog lub semiconductor silicon (Si). Tab sis sib nrug los ntawm nws, muaj ntau ntau lwm tus neeg. Piv txwv yog tej yam ntuj tso, xws semiconductor ntaub ntawv raws li blende (ZnS), cuprite (Cu ₂ O), galena (PBS) thiab ntau lwm tus neeg. Cov tsev neeg ntawm semiconductors, xws li semiconductors npaj nyob rau hauv lub chaw soj nstuam, nruab nrab yog ib qho ntawm feem ntau haiv neeg kawm ntawv cov ntaub ntawv paub rau cov txiv neej.

Characterization ntawm semiconductors

Ntawm 104 ntsiab ntawm lub periodic rooj yog hlau 79, 25 - nonmetals uas los ntawm tus 13 tshuaj ntsiab muaj semiconducting zog thiab 12 - dielectric. Main semiconductor feature muaj nyob rau hauv hais tias lawv conductivity tsub kom ho nrog ua kub. Thaum uas tsis muaj kub, lawv coj zoo li insulators, thiab thaum muaj kev kub - raws li conductors. Cov semiconductors yog txawv los ntawm hlau: hlau kuj yuav tsub proportionally rau qhov kev nce rau hauv kub.

Lwm qhov txawv ntawm lub semiconductor hlau yog hais tias lub kuj ntawm lub semiconductor txo nyob rau hauv tus ntawm lub teeb, thaum nyob rau hauv lub caij nyoog kawg no cov hlau yog tsis cuam tshuam. Tsis tas li ntawd lub conductivity ntawm semiconductors txawv thaum muab mus rau ib tug me nyiaj ntawm impurity.

Semiconductors yog pom cov tshuaj tebchaw uas sib txawv siv lead ua lug. Cov no tej zaum yuav hais xws li silicon thiab selenium, los yog ob lub tebchaw xws li gallium arsenide. Muaj ntau organic tebchaw, xws li polyacetylene, (CH) _n, - semiconductor cov ntaub ntawv. Tej yam semiconductors muaj magnetic (Cd _1-x Mn _x Te) los yog ferroelectric zog (SbSI). Lwm yam alloying nrog txaus ua superconductors (GeTe thiab SrTiO _3). Muaj ntau ntawm cov tshiab tshwm sim high-kub superconductors muaj nws yog xim hlau semiconducting theem. Piv txwv li, La ₂ CuO ₄ yog ib tug semiconductor, tab sis qhov uas muaj qhov hlau nrog Sr yuav sverhrovodnikom (La _1-x Sr _{x) 2} CuO _4.

Physics phau ntawv muab txhais raws li lub semiconductor khoom uas muaj ib tug hluav taws xob resistivity ntawm los ntawm 10 ^-4 mus rau 10 ⁷ ohms · m. Tej zaum ib txoj kev txhais. Lub dav ntawm lub forbidden band ntawm lub semiconductor - los ntawm 0 mus rau 3 eV. Co thiab cov semimetals - ib cov khoom uas muaj pes tsawg lub zog kis, thiab cov tshuaj yeeb dej caw nyob rau hauv uas nws tshaj W eV hu ua insulators. Muaj kev zam. Piv txwv li, ib tug semiconductor pob zeb diamond muaj ib tug dav txwv tsis pub cheeb tsam 6 eV, ib tug semi-insulating GaAs - 1,5 eV. GaN, ib cov khoom rau optoelectronic pab kiag li lawm nyob rau hauv cov kob xiav cheeb tsam, muaj ib tug txwv tsis pub band dav ntawm 3.5 eV.

lub zog kis

Valence orbitals ntawm atoms nyob rau hauv tus siv lead ua ntxaij ntoo yog muab faib ua ob pawg ntawm lub zog ntau ntau - ib tug dawb cheeb tsam, situated nyob rau theem siab tshaj plaws, thiab txiav txim qhov hluav taws xob conductivity ntawm semiconductors, thiab cov valence band, hauv qab no. Cov ntau ntau, nyob ntawm seb lub symmetry ntawm tus siv lead ua ntxaij ntoo qauv thiab atoms yuav tshuam los yog yuav spaced los ntawm txhua lwm yam. Nyob rau hauv lub caij nyoog kawg no cov ntaub ntawv muaj ib tug muaj zog sib, los yog nyob rau hauv lwm yam lus, nruab nrab ntawm lub forbidden band aav.

Lub chaw thiab lub filling theem yog txiav txim los ntawm lub conductive thaj chaw ntawm cov khoom. Raws li qhov no feature tshuaj muab faib los ntawm lub conductors, insulators, thiab semiconductors. Lub dav ntawm lub forbidden band ntawm lub semiconductor txawv 0.01-3 eV, lub zog kis ntawm lub dielectric tshaj 3 eV. Co vim lub overlap ntawm lub zog kis ntau ntau tsis tau.

Semiconductors thiab insulators, nyob rau hauv sib piv rau co, cov electrons yog lawm ua tus sau valence band thiab tus nyob ze free tsam, los yog cov conduction band, lub valence zog yog fenced tawm los ntawm kev sib tawg - feem ntawm txwv tsis pub energies ntawm electrons.

Nyob rau hauv dielectrics thermal zog los yog negligible hluav taws xob field yog tsis txaus yuav ua rau tus dhia los ntawm no kis, lub electrons yog tsis raug mus rau lub conduction band. Lawv tsis muaj peev xwm txav los ntawm tus siv lead ua ntxaij ntoo thiab ua muaj ntawm cov hluav taws xob tam sim no.

Yuav kom txhawb qhov hluav taws xob conductivity, ib tug electron nyob rau hauv lub valence theem yuav tsum tau muab lub zog, uas yuav txaus rau overcome lub zog kis. Tsuas yog thaum tus nqi ntawm lub zog haum yog tsis me dua tus nqi ntawm lub zog kis, yuav kis tau los ntawm cov valence electron rau ntawm cov conduction theem.

Nyob rau hauv cov ntaub ntawv uas, yog hais tias tus dav ntawm lub zog kis tshaj 4 eV, conductivity semiconductor excitation irradiation los yog cua sov yog zoo tsis yooj yim sua - lub excitation lub zog ntawm lub electrons nyob rau melting kub yog tsis txaus dhia lub zog kis los ntawm lub cheeb tsam. Thaum rhuab, tus siv lead ua melts ua ntej lub tshuab hluav taws xob conductivity. Tej yam muaj xws li quartz (tsib = 5,2 eV), pob zeb diamond (tsib = 5,1 eV), ntau ntsev.

Extrinsic thiab intrinsic conductivity semiconductor

Net semiconductor muaju muaj intrinsic conductivity. Tej semiconductors npe. Intrinsic semiconductor muaj vaj huam sib luag naj npawb ntawm cov qhov thiab dawb electrons. Thaum cua sov intrinsic conductivity ntawm semiconductors qab. Thaum qhov kub, muaj yog ib tug mob ntawm dynamic equilibrium nqi ntawm generated electron-qhov officers thiab tus naj npawb ntawm recombining electrons thiab qhov, uas nyob twj ywm qhov nyob rau hauv cov tej yam kev mob.

Lub xub ntiag ntawm impurities ho muaj feem xyuam rau cov hluav taws xob conductivity ntawm semiconductors. Ntxiv lawv tso cai heev ua rau tus xov tooj ntawm free electrons ntawm ib tug me me muaj pes tsawg tus ntawm qhov thiab nce tus naj npawb ntawm qhov nrog ib tug me me muaj pes tsawg tus ntawm electrons nyob rau hauv lub conduction theem. Impurity semiconductors - lub conductors muaj lub impurity conductivity.

Impurities yog yooj yim pub electrons yog hu ua pub. Donor impurities tej zaum yuav tshuaj hais nrog lub atoms, cov valence theem uas muaj ntau electrons tshaj lub atoms ntawm lub hauv paus khoom. Piv txwv li, phosphorus thiab Bismuth - ib tug silicon pub impurities.

Lub zog yuav tsum tau rau cov dhia ntawm ib tug electron nyob rau hauv lub conduction cheeb tsam, yog ua kom lub zog. Impurity semiconductor xav tau ib tug ntau tsawg ntawm nws tshaj hauv lub hauv paus khoom. Nrog ib tug me ntsis cua kub los yog lub teeb feem ntau tso electrons ntawm atoms ntawm lub impurity semiconductors. Muab sab laug lub atom yuav siv sij hawm ib tug electron qhov. Tab sis lub electron qhov recombination tsis muab qhov chaw. pub qhov conductivity yog negligible. Qhov no yog vim hais tias ib tug me me npaum li cas ntawm impurity atoms tsis pub dawb electrons feem ntau los ze zog mus rau lub qhov thiab los tuav nws. Electrons yog ib co qhov, tab sis yog tsis muaj peev xwm sau lawv vim tsis txaus zog.

Ib me ntsis ntxiv pub impurity ob peb txiav txim tsub kom lub xov tooj ntawm conduction electrons nyob rau hauv kev sib piv nrog rau cov xov tooj ntawm free electrons nyob rau hauv lub intrinsic semiconductor. Electrons ntawm no - lub ntsiab nqa khoom ntawm atomic nqi ntawm impurity semiconductors. Cov tshuaj mus rau lub n-hom semiconductors.

Impurities uas khi electrons ntawm lub semiconductor, nce lub xov tooj ntawm qhov nyob rau hauv nws, hu ua acceptor. Acceptor impurities yog tshuaj ntsiab nrog ib tug me me muaj pes tsawg tus ntawm electrons nyob rau hauv valence npaum li lub hauv paus ntawm lub semiconductor. Boron, gallium, indium - acceptor impurity nyob rau hauv pob zeb ntais.

Tus yam ntxwv ntawm tus semiconductor yog nyob rau nws siv lead ua qauv tsis xws luag. Qhov no ua rau cov yam tseem ceeb ntawm kev loj hlob tsis tshua muaj neeg ntshiab muaju. Cov ciaj ciam ntawm lub semiconductor conduction tshuaj los ntawm qhov sib ntxiv ntawm dopants. Silicon muaju doped nrog phosphorus (V pab pawg caij) uas yog ib tug neeg los mus tsim siv lead ua pob zeb ntais n-hom. Rau siv lead ua nrog ib tug p-hom silicon muab boron acceptor. Semiconductors compensated Fermi theem txav nws mus rau hauv nruab nrab ntawm lub band kis tsim nyob rau hauv no.

ib leeg-caij semiconductors

Cov feem ntau semiconductor yog, ntawm chav kawm, pob zeb ntais. Ua ke nrog lub teb chaws Yelemees, nws yog qhov chiv keeb ntawm ib tug loj chav kawm ntawv ntawm semiconductors uas muaj zoo ib yam li siv lead ua lug.

Qauv siv lead ua Si thiab GE yog tib yam li hais tias ntawm cov pob zeb diamond thiab α-tin. Nws koos txhua atom 4 nyob ze atoms uas tsim ib tug tetrahedron. Tej kev sib koom tes yog hu ua plaub lub sij hawm. Muaju tetradricheskoy daim ntawv cog lus steel puag rau lub electronics kev lag luam thiab ua si ib tug tseem ceeb luag hauj lwm nyob rau hauv niaj hnub siv tshuab. Ib co ntawm cov ntsiab V thiab VI ntawm lub periodic rooj pab pawg neeg kuj semiconductors. Piv txwv ntawm no hom ntawm semiconductors - phosphorus (P), sulfur (S), selenium (Se) thiab tellurium (Te). Cov semiconductors tej zaum yuav triple atoms (P), disubstituted (S, Se, Te) los yog ib tug plaub-fold kom sib haum. Raws li ib tug tshwm sim xws ntsiab yuav muaj nyob rau hauv ob peb txawv crystalline lug, thiab kuj yuav npaj nyob rau hauv daim ntawv ntawm cov iav. Piv txwv li, Se zus nyob rau hauv monoclinic thiab trigonal siv lead ua lug los yog raws li ib lub qhov rais (uas kuj yuav ntshai raws li ib tug polymer).

- Pob Zeb Diamond muaj zoo heev thermal conductivity, yav tom ntej cov neeg kho tshuab thiab kho qhov muag zog, siab txhua yam muaj zog. Lub dav ntawm lub zog kis - tsib = 5,47 eV.

- Silicon - semiconductor siv nyob rau hauv hnub ci hlwb, thiab amorphous daim ntawv no, - nyob rau hauv ib tug nyias zaj duab xis-hnub ci hlwb. Nws yog lub feem ntau siv nyob rau hauv semiconductor hnub ci hlwb, ib qho yooj yim los tsim, muaj zoo hluav taws xob thiab txhua yam khoom. tsib = 1,12 eV.

- Germanium - semiconductor siv nyob rau hauv lub gamma-ray spectroscopy, muaj kev kawm siab hnub ci hlwb. Siv nyob rau hauv thawj diodes thiab transistors. Nws yuav tsum tau tsawg tu tshaj silicon. tsib = 0,67 eV.

- Selenium - ib tug semiconductor, uas yog siv nyob rau hauv lub selenium rectifiers muaj ib tug siab tawg kuj thiab lub peev xwm yuav kho nws tus kheej.

Ob-caij tebchaw

Thaj chaw ntawm semiconductors tsim ntsiab 3 thiab 4 ntawm lub periodic rooj pawg zoo li lub thaj chaw ntawm tebchaw 4 pawg. Cov kev hloov ntawm lub 4 pawg ntawm cov ntsiab rau tebchaw 3-4 gr. Nws ua rau kev sib txuas lus tej vim ionic xwb thauj electrons los ntawm ib tug atom rau Atom 3 Group 4 pawg. Ionicity hloov lub thaj chaw ntawm semiconductors. Nws ua rau ib qho kev nce nyob rau hauv lub Coulomb zog thiab ion-ion sis lub zog kis electron band qauv. QAUV binary tebchaw ntawm no hom - indium antimonide, InSb, gallium arsenide GaAs, gallium antimonide GaSb, indium phosphide InP, txhuas antimonide AlSb, gallium phosphide GAP.

Ionicity nce thiab nws cov nuj nqis hlob ntau pawg nyob rau hauv lub tebchaw 2-6 tebchaw, xws li cadmium selenide, zinc sulfide, cadmium sulfide, cadmium telluride, zinc selenide. Raws li ib tug tshwm sim, feem ntau ntawm cov tebchaw 2-6 pab pawg txwv tsis pub band wider tshaj 1 eV, tsuas yog mercury tebchaw. Mercury Telluride - tsis muaj zog kis semiconductor, semi-hlau, zoo li α-tin.

Semiconductors 2-6 pab pawg nrog ib tug loj zog kis xyuas kev siv nyob rau hauv qhuav ntawm lasers thiab qhia. Binary pawg 6 2- compound nrog ib tug roj kis zog haum rau infrared receivers. Binary sib txuas ntawm cov ntsiab ntawm cov pab pawg 1-7 (cuprous bromide CuBr, AGI nyiaj iodide, tooj liab chloride CuCl) vim lub high ionicity muaj wider bandgap W eV. Lawv ua tsis tau semiconductors, thiab insulators. Crystal txoj kev loj hlob anchoring zog vim Coulomb interionic sis tswj structuring atoms ntsev nrog rau kev txiav txim, es tsis txhob ntawm lub quadratic tswj. Tebchaw 4-6 pawg - sulfide, ua telluride, tin sulfide - raws li semiconductors. Ionicity ntawm cov tshuaj yeej txhawb lub tsim sixfold kom sib haum. Ntau ionicity tsis txwv hauv lub xub ntiag lawv muaj ib tug heev nqaim band khoob, lawv muaj peev xwm yuav siv tau rau tau txais infrared tawg. Gallium nitride - ib tug compound pawg 3-5 nrog ib tug dav zog kis, nrhiav daim ntawv thov nyob rau hauv semiconductor lasers thiab lub teeb-emitting diodes kev khiav hauj lwm nyob rau hauv cov kob xiav ib feem ntawm lub spectrum.

- GaAs, gallium arsenide - xav tau tom qab tus thib ob silicon semiconductor yog feem ntau siv raws li ib tug substrate rau lwm conductors, piv txwv li, GaInNAs thiab InGaAs, nyob rau hauv setodiodah infrared, siab zaus transistors thiab ics, heev npaum solar hlwb, laser diodes, detectors ntawm nuclear kev kho. tsib = 1,43 eV, uas pab txoj kev lub hwj chim pab kiag li lawm yog muab piv nrog silicon. Nkig, muaj ntau impurities nyuaj los tsim.

- ZnS, zinc sulfide - zinc ntsev ntawm hydrogen sulphide nrog lub forbidden band ncig chaw thiab 3,54 3,91 eV, siv nyob rau hauv lasers thiab raws li ib tug phosphor.

- SNS, tin sulfide - semiconductor siv nyob rau hauv photoresistors thiab photodiodes, tsib = 1,3 thiab 10 eV.

oxides

Cov hlau oxides dua yog zoo heev insulators, tab sis muaj kev zam. Piv txwv ntawm no hom ntawm semiconductors - npib tsib xee oxide, tooj liab oxide, cobalt oxide, tooj liab dioxide, hlau oxide, europium oxide, zinc oxide. Txij li thaum tooj liab dioxide tshwm sim raws li cov mineral cuprite, nws cov khoom tau kawm sib. Tus txheej txheem rau cov kev sau qoob rau no hom ntawm semiconductor yog tseem tsis tau nkaus ntshiab, yog li lawv siv yog tseem tsawg. Tsuas yog ib tug yog zinc oxide (ZnO), compound pawg 2-6, yog siv raws li lub transducer thiab nyob rau hauv qhuav ntawm nplaum tapes thiab plasters.

Qhov teeb meem no tau hloov dramatically tom qab superconductivity sab nyob rau hauv ntau lub tebchaw ntawm tooj liab nrog rau oxygen. Tus thawj kub superconductor qhib Bednorz thiab Muller, twb compound semiconductor raws li nyob rau hauv La ₂ CuO _4, lub zog kis ntawm 2 eV. Pauv divalent trivalent lanthanum, barium los yog strontium, nkag mus rau hauv lub semiconductor xwb muaj ntawm qhov. Tau raws li qhov tsim nyog qhov concentration ua La ₂ CuO ₄ superconductor. Thaum lub sij hawm no, lub siab tshaj plaws kub ntawm txoj kev hloov mus rau lub superconducting lub xeev yog compound HgBaCa ₂ Cu ₃ O _8. Thaum kub siab, nws cov nqi yog 134 K.

ZnO, zinc oxide varistor yog siv, xiav lub teeb-emitting diodes, roj sensors, lom sensors, coatings qhov rais rau muaj kev cuam tshuam infrared teeb, raws li ib tug neeg xyuas pib nyob rau hauv LCD qhia thiab hnub ci roj teeb. tsib = 3,37 eV.

layered muaju

Ob chav tebchaw zoo li diiodide lead, gallium selenide thiab molybdenum disulphide txawv fawm kib siv lead ua qauv. Cov khaubncaws sab nraud povtseg yog covalent bonds ntawm loj zog, muaj zog tshaj li lub van ua dawb Waals bonds ntawm cov khaubncaws sab nraud povtseg lawv tus kheej. Semiconductors xws hom nthuav vim hais tias cov electrons coj nyob rau hauv khaubncaws sab nraud povtseg ntawm ib tug quasi-ob-seem. Sis ntawm khaubncaws sab nraud povtseg yog hloov los ntawm qhia sab nraum atoms - intercalation.

Hlis _2, molybdenum disulfide yog siv nyob rau hauv siab zaus detectors, rectifiers, memristor, transistors. tsib = 1,23 thiab 1.8 eV.

organic semiconductors

Piv txwv ntawm semiconductors rau lub hauv paus ntawm cov organic tebchaw - naphthalene, polyacetylene (CH _{2) n,} anthracene, polydiacetylene, ftalotsianidy, polyvinylcarbazole. Organic semiconductors muaj ib tug kom zoo dua li uas tsis yog-organic: lawv yog cov yooj yim mus impart tej yam zoo. Tshuaj nrog conjugate bonds tsim C = C-C = muaj ntau yam pauv loj kho qhov muag uas tsis yog-linearity thiab, vim rau qhov no, nyob rau hauv optoelectronics thov. Ntxiv mus, lub zog band kis organic semiconductor compound ntawm lub mis txawv hloov uas yooj yim npaum li ntawd ntawm cov pa semiconductors. Crystalline allotropes ntawm carbon fullerenes, graphene, nanotubes - kuj semiconductors.

- Fullerene muaj ib tug qauv nyob rau hauv daim ntawv ntawm ib tug kaw convex polyhedron ugleoroda txawm tooj ntawm atoms. Ib tug doping fullerene C ₆₀ nrog ib tug alkali hlau transforms nws mus rau hauv ib tug superconductor.

- graphite carbon monoatomic txheej yog tsim, yog kev cob cog rua nyob rau hauv ib tug ob-dimensional hexagonal lattice. Cov ntaub ntawv muaj conductivity thiab lub electron muaj, siab rigidity

- nanotubes yog dov rau hauv ib tug raj graphite phaj muaj ib lub cheeb ntawm ob peb nanometers. Cov ntaub ntawv ntawm cov pa roj carbon muaj cog lus zoo heev nyob rau hauv nanoelectronics. Nyob rau hauv lub coupling tej zaum yuav yog xim hlau los yog semiconductor zoo.

magnetic semiconductors

Tebchaw nrog magnetic ions ntawm europium thiab manganese muaj mas magnetic thiab semiconducting zog. Piv txwv ntawm no hom ntawm semiconductors - europium sulfide, selenide europium thiab khoom dlaws, xws Cd _1-x Mn _x Te. Cov ntsiab lus ntawm cov magnetic ions muaj feem xyuam rau tag nrho ob qho tshuaj muaj magnetic zog xws li ferromagnetism thiab antiferromagnetism. Semimagnetic semiconductors - yog ib tug nyuaj magnetic semiconductors kev daws teeb meem uas muaj magnetic ions nyob rau hauv uas tsis muaj concentration. Tej khoom dlaws nyiam cov xim uas koj prospect thiab kuj zoo kawg tej zaum tau daim ntaub ntawv. Piv txwv li, nyob rau hauv sib piv rau cov uas tsis yog-sib nqus semiconductors, lawv yuav ncav cuag ib lab lub sij hawm loj Faraday kev sib hloov.

Muaj zog magnetooptical los ntawm magnetic semiconductors cia lawv siv rau kho qhov muag tes taws los piav. Perovskites, zoo li Mn _0,7 Ca _0,3 O _3, nws cov khoom yog superior rau hlau-semiconductor hloov, uas ncaj dependence rau lub magnetic teb tau nyob rau hauv lub phenomenon ntawm giant Magneto-resistivity. Lawv yog siv nyob rau hauv xov tooj cua, kho qhov muag pab kiag li lawm, uas yog tswj los ntawm ib tug sib nqus teb, ib tug microwave waveguide pab kiag li lawm.

semiconductor ferroelectrics

Qhov no hom muaju yog tsiag ntawv los ntawm muaj nyob rau hauv lawv cov hluav taws xob lub sij hawm thiab tshwm sim ntawm txawj polarization. Piv txwv li, xws zog yog semiconductors ua titanate PbTiO _3, barium titanate BaTiO _3, germanium telluride, GeTe, tin telluride SnTe, uas thaum uas tsis muaj kub muaj ferroelectric zog. Cov ntaub ntawv no yog siv nyob rau hauv nonlinear kho qhov muag, piezoelectric sensors thiab nco kiag li lawm.

Ib tug ntau yam ntawm semiconductor ntaub ntawv

Nyob rau hauv tas li ntawd mus semiconductor ntaub ntawv hais saum toj no, muaj ntau ntau lwm tus neeg uas tsis poob rau hauv ib tug ntawm cov hom. Tebchaw ntawm mis 1-3-5 ntsiab ₂ (AgGaS ₂₎ thiab 2-4-5 ₂ (ZnSiP ₂₎ tsim ib chalcopyrite siv lead ua qauv. Hu rau tetrahedral tebchaw analogous semiconductors 3-5 thiab 2-6 pab pawg nrog ib tug zinc blende siv lead ua qauv. Tebchaw uas tsim semiconductor ntsiab 5 thiab 6 pawg (xws li cov Raws li ₂ Se _3), - tus semiconductor nyob rau hauv daim ntawv uas siv lead ua los yog iav. Chalcogenides ntawm Bismuth thiab antimony yog siv nyob rau hauv semiconductor thermoelectric generators. Cov khoom ntawm no hom ntawm semiconductor yog tsis tshua muaj nthuav, tab sis lawv tsis tau tau chaw vim lub tsawg daim ntawv thov. Txawm li cas los, qhov tseeb hais tias lawv muaj nyob, muaj tseeb nrog qhov xub ntiag ntawm tseem tsis tau siab txug lub tshav pob ntawm semiconductor physics.