Keeb kwm ntawm LED txoj kev loj hlob
Kev tshawb pom ntawm semiconductor PN junction luminescence tuaj yeem taug qab mus rau xyoo 1920s. Fabkis tus kws tshawb fawb OWLossow thawj zaug pom qhov tshwm sim luminescence no thaum nws tab tom kawm SiC detectors. Vim muaj kev txwv ntawm kev npaj cov khoom siv thiab cov cuab yeej siv thev naus laus zis thaum lub sijhawm ntawd, qhov kev tshawb pom tseem ceeb no tsis tau siv sai. Txog rau plaub caug xyoo tom qab, nrog rau kev nce qib ntawm III-V pab pawg cov ntaub ntawv thiab cov cuab yeej siv tshuab, tib neeg thaum kawg tau ua tiav cov txiaj ntsig ntawm GaAsP lub teeb-emitting diode emitting lub teeb liab, uas yog tsim los ntawm GE raws li qhov ntsuas ntsuas. Txij thaum ntawd los, vim muaj kev txhim kho ntxiv ntawm GaAs, Gap thiab lwm yam ntaub ntawv tshawb fawb thiab cuab yeej cuab yeej technology, ntxiv rau qhov sib sib zog nqus liab LEDs, LED cov cuab yeej suav nrog txiv kab ntxwv, daj, daj-ntsuab thiab lwm yam xim kuj tau tshwm sim hauv kev ua lag luam coob.
Rau ntau yam, cov khoom siv LED xws li Gap thiab GaAsP muaj qhov ua haujlwm qis qis, thiab lub teeb siv feem ntau yog qis dua 10mcd, uas tsuas yog siv tau rau lub hom phiaj sab hauv tsev. Txawm hais tias cov khoom siv AlGaAs nkag mus rau hauv cheeb tsam dhia tsis ncaj, qhov luminous efficiency poob sai heev. Nrog rau kev nce qib ntawm cov ntaub ntawv semiconductor thiab cov cuab yeej siv tshuab, tshwj xeeb tshaj yog kev loj hlob ntawm cov txheej txheem epitaxial xws li MOCVD, thaum ntxov 1990s, Nichia ntawm Nyiv thiab Cree ntawm Tebchaws Meskas tau siv MOCVD thev naus laus zis hauv GaN-based LED epitaxial wafers nrog cov qauv siv tau. Kev loj hlob tiav ntawm sapphire thiab SiC substrates, thiab xiav, ntsuab thiab violet LED cov khoom siv nrog lub siab ci tau tsim.
Qhov tshwm sim ntawm ultra-high brightness LED li tau qhib qhov kev cia siab zoo heev rau kev nthuav dav ntawm LED daim ntawv thov teb. Thawj qhov yog tias qhov nce ntawm qhov ci ci ua rau daim ntawv thov ntawm cov khoom siv LED txav ntawm sab hauv tsev mus rau sab nraum zoov. Txawm nyob rau hauv lub hnub muaj zog, cov cd-theem LED raj tseem tuaj yeem ci ntsa iab thiab muaj xim zoo nkauj. Tam sim no, nws tau dav siv nyob rau hauv sab nraum zoov loj-screen zaub, tsheb xwm txheej qhia, tsheb teeb, LCD backlight thiab dav teeb pom kev zoo. Qhov thib ob feature ntawm ultra-ci LEDs yog qhov txuas ntxiv ntawm emission wavelength. Qhov tshwm sim ntawm InGaAlP cov cuab yeej txuas ntxiv cov emission band mus rau thaj tsam luv-yoj daj-ntsuab ntawm 570 nm, thaum GaN-raws li cov cuab yeej txuas ntxiv txuas ntxiv cov emission wavelength mus rau ntsuab, xiav, thiab violet bands. Nyob rau hauv txoj kev no, cov khoom siv LED tsis yog tsuas yog ua rau lub ntiaj teb muaj yeeb yuj, tab sis kuj ua rau nws muaj peev xwm tsim cov khoom siv hluav taws xob hauv lub xeev dawb. Piv nrog rau cov teeb pom kev zoo, cov khoom siv LED yog qhov chaw txias txias nrog lub neej ntev thiab kev siv hluav taws xob tsawg. Qhov thib ob, cov khoom siv LED kuj muaj qhov zoo ntawm qhov me me, ruaj khov thiab ruaj khov, tsis tshua muaj hluav taws xob ua haujlwm, cov lus teb ceev ceev, thiab kev sib txuas yooj yim nrog cov khoos phis tawj. Kev txheeb cais qhia tau hais tias nyob rau hauv tsib lub xyoos dhau los ntawm lub xyoo pua nees nkaum, daim ntawv thov kev lag luam ntawm high-brightness LED cov khoom tau tuav ib qho kev loj hlob ntawm ntau tshaj 40 feem pua. Nrog rau kev rov qab los ntawm lub ntiaj teb kev lag luam thiab pib ntawm qhov project teeb pom kev zoo, nws ntseeg tau tias kev tsim khoom thiab kev siv ntawm LED yuav ua rau muaj kev vam meej dua.
