Ua rau LED's Heat Generation
Ib yam li cov teeb pom kev zoo ib yam, semiconductor emitting diodes (LEDs) kuj tsim kom muaj cua sov thaum lub sijhawm ua haujlwm, nyob ntawm qhov kev ua tau zoo ntawm luminous tag nrho. Nyob rau hauv qhov kev txiav txim ntawm kev siv hluav taws xob siv hluav taws xob, hluav taws xob ntawm cov hluav taws xob thiab qhov sib txuas ua ke los tsim cov hluav taws xob hluav taws xob, thiab lub teeb hluav taws xob nyob ze ntawm PN kev sib tshuam yuav tsum dhau los ntawm qhov nruab nrab semiconductor thiab ntim nruab nrab ntawm cov nti nws tus kheej kom ncav cuag sab nraud (cua). Kev txhaj tshuaj tam sim no, hluav taws xob luminescence quantum efficiency, nti sab nraud lub teeb extraction efficiency, thiab lwm yam, qhov kawg nkaus xwb 30-40% ntawm lub zog nkag mus rau hauv lub teeb lub zog, thiab qhov seem 60-70% ntawm nws lub zog feem ntau tshwm sim nyob rau hauv ib qho tsis- radiation complex daim ntawv ntawm dot-matrix vibration conversion tshav kub.
Qhov nce ntawm nti kub yuav txhim khu qhov tsis yog hluav taws xob complex, ntxiv zog rau lub luminous efficiency. Vim tias tib neeg xav tias lub zog siab LEDs tsis muaj cua sov, qhov tseeb, lawv ua. Cov cua sov ntau yooj yim ua rau muaj ntau yam teeb meem thaum siv. Tsis tas li ntawd, ntau tus neeg siv lub zog siab LEDs thawj zaug thiab tsis nkag siab yuav ua li cas daws cov teeb meem thermal, ua kom muaj kev ntseeg siab ntau dhau los ua qhov teeb meem tseem ceeb. Yog li ntawm no yog qee cov lus nug cia peb xav txog: Puas yog LEDs puas muaj cua sov tsim? Nws tuaj yeem tsim hluav taws xob ntau npaum li cas? Lub LED tsim hluav taws xob ntau npaum li cas?
Nyob rau pem hauv ntej voltage ntawm LED, cov electrons tau txais lub zog los ntawm lub hwj chim mov. Nyob rau hauv kev tsav tsheb ntawm lub teb hluav taws xob, hluav taws xob ntawm PN kev sib tshuam tau kov yeej, thiab kev hloov pauv ntawm thaj av N mus rau thaj tsam P tshwm sim. Cov electrons recombine nrog lub qhov nyob rau hauv cheeb tsam P. Txij li thaum cov hluav taws xob dawb ntws mus rau hauv thaj av P muaj lub zog ntau dua li cov hluav taws xob valence hauv thaj av P, cov hluav taws xob rov qab mus rau lub xeev qis zog thaum lub sij hawm recombination, thiab lub zog tshaj tawm hauv daim ntawv ntawm photons. Lub wavelength ntawm lub emitted photon muaj feem xyuam rau lub zog sib txawv Piv txwv li. Nws tuaj yeem pom tias thaj chaw teeb pom kev zoo yog nyob ze ntawm PN kev sib tshuam, thiab lub teeb emission yog qhov tshwm sim ntawm lub zog tso tawm los ntawm recombination ntawm electrons thiab qhov. Nyob rau hauv ib tug semiconductor diode, electrons yuav ntsib kev tiv thaiv thaum lub sij hawm tag nrho cov taug kev los ntawm lub semiconductor cheeb tsam mus rau lub semiconductor cheeb tsam. Tsuas yog los ntawm txoj cai, cov qauv ntawm lub cev ntawm semiconductor diode tsuas yog los ntawm lub hauv paus ntsiab lus, tus naj npawb ntawm cov electrons tawm ntawm qhov tsis zoo electrode thiab cov electrons rov qab mus rau qhov zoo electrode ntawm semiconductor diode yog sib npaug. Ordinary diodes, thaum electron-qhov khub recombination tshwm sim, vim qhov zoo ntawm lub zog theem sib txawv Piv txwv li, lub tso tawm photon spectrum tsis nyob rau hauv qhov pom ntau yam.
Nyob rau hauv txoj kev hauv lub diode, electrons siv lub zog vim muaj qhov tsis kam. Lub zog siv tau ua raws li cov cai ntawm electronics:
P = I2 R = I2 (RN + + RP) + IVTH
Lus Cim: RN yog lub cev tiv thaiv ntawm N cheeb tsam
VTH yog qhov hloov hluav taws xob ntawm PN kev sib tshuam
RP yog qhov tsis kam ntawm thaj tsam P
Cov cua sov tsim los ntawm lub zog siv yog:
Q = Pt
Qhov twg: t yog lub sij hawm lub diode energized.
Nyob rau hauv qhov tseeb, LED tseem yog ib tug semiconductor diode. Yog li ntawd, thaum lub LED ua hauj lwm nyob rau hauv cov kev taw qhia pem hauv ntej, nws cov txheej txheem ua hauj lwm raws li cov lus piav qhia saum toj no. Lub zog hluav taws xob nws siv yog:
P LED = U LED × I LED
Qhov twg: U LED yog qhov hluav taws xob rau pem hauv ntej hla lub teeb ci LED
Kuv LED yog tam sim no ntws los ntawm LED
Cov hluav taws xob siv hluav taws xob tau hloov mus rau hauv tshav kub thiab tso tawm:
Q NP LED × t
Lus Cim: t yog lub sijhawm siv hluav taws xob
Qhov tseeb, lub zog tso tawm thaum lub tshuab hluav taws xob sib txuas nrog lub qhov nyob hauv cheeb tsam P tsis ncaj qha los ntawm cov khoom siv hluav taws xob sab nraud, tab sis vim tias cov hluav taws xob nyob hauv cheeb tsam N, thaum tsis muaj hluav taws xob sab nraud, nws lub zog siab dua. tshaj li ntawm thaj tsam P. Valence electron theem siab dua Eg. Thaum nws mus txog thaj tsam P thiab rov sib txuas nrog lub qhov los ua valence electrons hauv thaj av P, nws yuav tso tawm ntau lub zog. Qhov loj ntawm Eg yog txiav txim los ntawm cov khoom siv nws tus kheej thiab tsis muaj dab tsi cuam tshuam nrog cov hluav taws xob sab nraud. Lub luag haujlwm ntawm cov khoom siv hluav taws xob sab nraud rau lub tshuab hluav taws xob yog thawb nws kom txav mus los thiab kov yeej lub luag haujlwm ntawm PN kev sib tshuam.
Tus nqi hluav taws xob tsim los ntawm LED tsis muaj dab tsi ua rau lub teeb pom kev zoo; tsis muaj kev sib raug zoo ntawm qhov feem pua ntawm cov hluav taws xob hluav taws xob tsim lub teeb, thiab cov feem pua ntawm cov hluav taws xob hluav taws xob ua kom sov. Los ntawm kev nkag siab txog cov ntsiab lus ntawm kev tsim hluav taws xob, kev tiv thaiv thermal thiab kev sib txuas ntawm cov hluav taws xob muaj zog LEDs thiab qhov muab los ntawm cov qauv theoretical thiab kev ntsuas thermal, peb tuaj yeem kawm txog cov qauv ntim tiag tiag, kev ntsuam xyuas thiab cov khoom siv ntawm lub zog LEDs. Nws yuav tsum raug sau tseg tias kev tswj cov cua sov yog qhov teeb meem tseem ceeb ntawm theem tam sim no ntawm kev ua haujlwm qis ntawm cov khoom siv LED. Hauv paus kev txhim kho luminous efficiency kom txo tau cov tiam ntawm tshav kub zog yog nyob rau hauv qab ntawm lub kettle. Qhov no yuav tsum tau chip manufacturing, LED ntim thiab daim ntawv thov cov khoom tsim. Kev vam meej hauv txhua yam.
