Umgaqo wokukhanya we-LED

Konkeisibane somsebenzi esinokutshajwa kwakhona, isibane sokukhempisha esiphathwayokwayeisibane sentloko esisebenza ngeendlela ezininziSebenzisa uhlobo lwebhalbhu ye-LED. Ukuze uqonde umgaqo we-diode led, qala ngokuqonda ulwazi olusisiseko lwee-semiconductors. Iimpawu zokuqhuba zezixhobo ze-semiconductor ziphakathi kwee-conductors kunye nee-insulators. Iimpawu zayo ezikhethekileyo zezi: xa i-semiconductor ivuselelwa kukukhanya kwangaphandle kunye neemeko zobushushu, amandla ayo okuqhuba aya kutshintsha kakhulu; Ukongeza inani elincinci lokungcola kwi-semiconductor ecocekileyo kwandisa kakhulu amandla ayo okuqhuba umbane. I-Silicon (Si) kunye ne-germanium (Ge) zezona semiconductors zisetyenziswa kakhulu kwii-elektroniki zanamhlanje, kwaye ii-electron zazo zangaphandle zine. Xa ii-athomu ze-silicon okanye ze-germanium zenza i-crystal, ii-athomu ezikufutshane ziyasebenzisana, ukuze ii-electron zangaphandle zabelwane ngee-athomu ezimbini, ezenza isakhiwo se-covalent bond kwi-crystal, esisakhiwo se-molecular esinamandla amancinci okukhawulelana. Kwiqondo lobushushu begumbi (300K), ukufudumala kobushushu kuya kwenza ezinye ii-electron zangaphandle zithole amandla aneleyo okuqhekeka kwi-covalent bond kwaye zibe zii-electron ezikhululekileyo, le nkqubo ibizwa ngokuba yi-intrinsic excitation. Emva kokuba i-electron ingabotshelelwanga ukuba yi-electron ekhululekileyo, isithuba sishiywa kwi-covalent bond. Esi sithuba sibizwa ngokuba ngumngxuma. Imbonakalo yomngxuma luphawu olubalulekileyo oluhlula i-semiconductor kwi-conductor.

Xa inani elincinci lokungcola kwe-pentavalent okufana ne-phosphorus kongezwa kwi-intrinsic semiconductor, iya kuba ne-electron eyongezelelweyo emva kokwenza i-covalent bond kunye nezinye ii-atoms ze-semiconductor. Le electron eyongezelelweyo ifuna amandla amancinci kakhulu ukuze isuse i-bond kwaye ibe yi-free electron. Olu hlobo lwe-uncleansing semiconductor lubizwa ngokuba yi-electronic semiconductor (N-type semiconductor). Nangona kunjalo, ukongeza inani elincinci lokungcola kwe-trivalent elemental (njenge-boron, njl.njl.) kwi-intrinsic semiconductor, kuba inee-electron ezintathu kuphela kumaleko wangaphandle, emva kokwenza i-covalent bond kunye nee-atoms ze-semiconductor ezijikelezileyo, kuya kudala isithuba kwi-crystal. Olu hlobo lwe-uncleansing semiconductor lubizwa ngokuba yi-hole semiconductor (P-type semiconductor). Xa ii-N-type kunye nee-P-type semiconductors zidityanisiwe, kukho umahluko kuxinzelelo lwee-free electron kunye neengxunya kwindawo ezidibana kuyo. Zombini ii-electron kunye neengxunya ziyasasazeka ziye kuxinzelelo oluphantsi, zishiya ii-ion ezitshajiweyo kodwa ezingashukumiyo ezitshabalalisa ukungathathi cala kombane kokuqala kwemimandla ye-N-type kunye ne-P-type. Ezi particles zitshajiweyo ezingashukumiyo zihlala zibizwa ngokuba zii-space charges, kwaye zixinene kufutshane nojongano lweendawo ze-N kunye ne-P ukuze zenze ummandla omncinci kakhulu we-space charge, owaziwa ngokuba yi-PN junction.

Xa kusetyenziswa i-forward bias voltage kuzo zombini iziphelo ze-PN junction (i-voltage elungileyo kwelinye icala le-P-type), imingxunya kunye nee-elektroni ezikhululekileyo ziyajikelezana, zenze intsimi yombane yangaphakathi. Imingxunya esandula ukufakwa emva koko idibana kwakhona nee-elektroni ezikhululekileyo, ngamanye amaxesha ikhupha amandla agqithisileyo ngendlela yee-photon, okukukhanya esikubonayo kukhutshwa zii-LED. I-spectrum enjalo incinci, kwaye ekubeni into nganye ine-band gap eyahlukileyo, ubude bamaza ee-photon ezikhutshwayo bahlukile, ngoko ke imibala yee-LED imiselwa zizinto ezisisiseko ezisetyenzisiweyo.