Tag nrhoLub teeb ua haujlwm Rechargeable, portable camping teebthiabmultifunctional headlampsiv lub LED teeb hom.Yuav kom nkag siab txog lub hauv paus ntsiab lus ntawm diode coj, ua ntej kom nkag siab txog cov kev paub ntawm semiconductors.Cov khoom siv hluav taws xob ntawm cov khoom siv semiconductor yog nruab nrab ntawm cov conductors thiab insulators.Nws cov yam ntxwv tshwj xeeb yog: thaum lub semiconductor txhawb nqa los ntawm cov teeb pom kev sab nraud thiab cua sov, nws lub peev xwm conductive yuav hloov pauv loj;Ntxiv me me ntawm impurities rau ib tug ntshiab semiconductor ho ua rau nws muaj peev xwm ua hluav taws xob.Silicon (Si) thiab germanium (Ge) yog cov feem ntau siv semiconductors hauv cov khoom siv hluav taws xob niaj hnub no, thiab lawv cov hluav taws xob sab nraud yog plaub.Thaum silicon los yog germanium atoms tsim ib lub siv lead ua, cov atoms nyob sib ze sib cuam tshuam nrog ib leeg, yog li ntawd cov electrons sab nrauv los sib koom los ntawm ob lub atoms, uas tsim cov qauv sib cog lus hauv cov siv lead ua, uas yog cov qauv molecular uas muaj peev xwm txwv me ntsis.Nyob rau hauv chav tsev kub (300K), thermal excitation yuav ua rau ib co sab nrauv electrons tau txais lub zog txaus los rhuav tshem ntawm covalent daim ntawv cog lus thiab ua dawb electrons, cov txheej txheem no hu ua intrinsic excitation.Tom qab lub tshuab hluav taws xob tsis tau ua kom dhau los ua ib qho hluav taws xob dawb, qhov chaw seem tshuav nyob rau hauv covalent daim ntawv cog lus.Qhov chaw seem no yog hu ua lub qhov.Cov tsos ntawm lub qhov yog ib qho tseem ceeb feature uas distinguishes ib tug semiconductor los ntawm ib tug conductor.
Thaum ib qho me me ntawm pentavalent impurity xws li phosphorus ntxiv rau hauv cov khoom siv hluav taws xob, nws yuav muaj cov khoom siv hluav taws xob ntxiv tom qab tsim cov ntawv cog lus nrog lwm cov semiconductor atoms.Cov hluav taws xob ntxiv no tsuas yog xav tau lub zog me me kom tshem tawm ntawm daim ntawv cog lus thiab dhau los ua cov hluav taws xob dawb.Hom impurity semiconductor no hu ua electronic semiconductor (N-type semiconductor).Txawm li cas los xij, ntxiv me me ntawm trivalent elemental impurities (xws li boron, thiab lwm yam) rau cov khoom siv hluav taws xob, vim tias nws tsuas muaj peb lub electrons nyob rau hauv txheej txheej, tom qab tsim ib daim ntawv cog lus nrog cov semiconductor atoms nyob ib puag ncig, nws yuav tsim qhov chaw seem. hauv crystal.Hom impurity semiconductor no hu ua qhov semiconductor (P-hom semiconductor).Thaum N-hom thiab P-hom semiconductors sib xyaw ua ke, muaj qhov sib txawv ntawm qhov sib txawv ntawm cov hluav taws xob dawb thiab qhov ntawm lawv qhov sib txuas.Ob qho tib si electrons thiab qhov yog diffused mus rau qis concentration, tawm hauv qab them tab sis immobile ions uas rhuav tshem cov thawj hluav taws xob nruab nrab ntawm N-hom thiab P-hom cheeb tsam.Cov immobile charged hais feem ntau hu ua qhov chaw tsub nqi, thiab lawv yog concentrated nyob ze ntawm lub interface ntawm N thiab P cheeb tsam los tsim ib tug heev nyias cheeb tsam ntawm qhov chaw nqi, uas yog hu ua PN hlws ris.
Thaum ib qho hluav taws xob rau pem hauv ntej yog siv rau ob qho kawg ntawm PN kev sib tshuam (qhov zoo voltage rau ib sab ntawm P-hom), lub qhov thiab cov hluav taws xob dawb txav ib ncig, tsim kom muaj hluav taws xob sab hauv.Cov qhov tshiab txhaj tshuaj tom qab ntawd rov ua dua nrog cov hluav taws xob dawb, qee zaum tso tawm lub zog ntau dhau ntawm photons, uas yog lub teeb uas peb pom tawm los ntawm leds.Xws li ib qho spectrum yog qhov nqaim, thiab txij li txhua yam khoom muaj qhov sib txawv ntawm qhov sib txawv, lub wavelengths ntawm photons emissions txawv, yog li cov xim ntawm leds yog txiav txim los ntawm cov ntaub ntawv yooj yim siv.
Post lub sij hawm: May-12-2023