I-LED yosiko iguqule inkambu yokukhanyisa nesibonisi ngenxa yokusebenza kwayo okuphezulu ngokusebenza kahle, ukuzinza nosayizi wedivayisi. Ama-LED ngokuvamile ayizitaki zamafilimu ama-semiconductor azacile anobukhulu obuseceleni bamamilimitha, mancane kakhulu kunamadivayisi endabuko njengama-incandescent bulb namashubhu e-cathode. Kodwa-ke, izinhlelo zokusebenza ze-optoelectronic ezivelayo, ezifana neqiniso elibonakalayo nelingeziwe, zidinga ama-LED ngosayizi wama-microns noma ngaphansi. Ithemba ukuthi i-micro - noma i-submicron scale LED (µleds) iyaqhubeka nokuba nezimfanelo eziningi eziphakeme ama-led endabuko asenazo kakade, njengokuphuma kwezinto ezinzile, ukusebenza kahle okuphezulu nokukhanya, ukusetshenziswa kwamandla aphansi kakhulu, nokuphuma kombala ogcwele, kuyilapho incane ngokuphindwe izikhathi eziyisigidi endaweni, ivumela izibonisi ezihlangene. Ama-chips anjalo angavula indlela yamasekethe ezithombe ezinamandla kakhulu uma engakhuliswa i-single-chip ku-Si futhi ahlanganiswe ne-complementary metal oxide semiconductor (CMOS) electronics.
Kodwa-ke, kuze kube manje, ama-µled anjalo ahlala engaqondakali, ikakhulukazi ebangeni le-wavelength ekhishwayo eluhlaza ukuya kokubomvu. Indlela yendabuko eholwa ngu-µ inqubo yokuya phezulu phansi lapho amafilimu e-InGaN quantum well (QW) eqoshwa kumadivayisi anesilinganiso esincane ngenqubo yokubhala. Nakuba ifilimu encane esekelwe ku-InGaN QW-based tio2 µleds idonse ukunakwa okukhulu ngenxa yezakhiwo eziningi ezinhle kakhulu ze-InGaN, njengokuthuthwa kwenkampani yenethiwekhi ephumelelayo kanye nokushuna kwe-wavelength kulo lonke uhla olubonakalayo, kuze kube manje bebelokhu bekhungethwe yizinkinga ezifana ne-side-wall. ukugqwala okuba kubi kakhulu njengoba usayizi wedivayisi uncipha. Ukwengeza, ngenxa yokuba khona kwezinkambu ze-polarization, banokungaqini kwe-wavelength/umbala. Kule nkinga, izixazululo ze-InGaN ezingezona ze-polar ne-semi-polar kanye ne-photonic crystal cavity ziye zahlongozwa, kodwa azigculisi okwamanje.
Ephepheni elisha elishicilelwe ku-Light Science and Applications, abacwaningi abaholwa nguZetian Mi, uprofesa wase-University of Michigan, u-Annabel, baye bahlakulela i-submicron esikalini esiluhlaza se-LED iii - i-nitride enqoba lezi zithiyo unomphela. Lawa ma-µled ahlanganiswe nge-epitaxy ye-molecular molecular epitaxy ekhethiwe yesifunda esizwa nge-plasma. Ngokuphambene kakhulu nendlela evamile yokuya phezulu, i-µled lapha iqukethe ama-nanowires, ngayinye engu-100 kuya ku-200 nm ububanzi, ehlukaniswa ngamashumi ama-nanometers. Le ndlela yokuya phezulu igwema ukulimala kokugqwala kodonga olusemaceleni.
Ingxenye yedivayisi ekhipha ukukhanya, eyaziwa nangokuthi isifunda esisebenzayo, yakhiwe izakhiwo ze-core-shell multiple quantum well (MQW) ezibonakala nge-nanowire morphology. Ikakhulukazi, i-MQW iqukethe umthombo we-InGaN kanye nomgoqo we-AlGaN. Ngenxa yomehluko ekufudukeni kwe-athomu ye-adsorbed yezinto ze-Group III i-indium, i-gallium ne-aluminium ezindongeni eziseceleni, sithole ukuthi i-indium yayingekho ezindongeni ezisemaceleni ze-nanowires, lapho igobolondo le-GaN/AlGaN laligoqe khona umgogodla we-MQW njenge-burrito. Abacwaningi bathola ukuthi okuqukethwe kwe-Al kuleli gobolondo le-GaN/AlGaN kwehle kancane kancane ukusuka ohlangothini lomjovo we-electron we-nanowires kuya ohlangothini lomjovo wembobo. Ngenxa yomehluko emikhakheni yangaphakathi ye-polarization ye-GaN ne-AlN, i-gradient yevolumu enjalo yokuqukethwe kwe-Al kungqimba ye-AlGaN ingenisa ama-electron amahhala, ageleza kalula kumongo we-MQW futhi adambise ukungazinzi kombala ngokunciphisa inkambu ye-polarization.
Eqinisweni, abacwaningi bathole ukuthi kumadivayisi angaphansi kwe-micron eyodwa ububanzi, ukuphakama kwe-wavelength ye-electroluminescence, noma ukukhishwa kokukhanya okubangelwa manje, kuhlala kungashintshile ngohlelo lobukhulu boshintsho lomjovo wamanje. Ngaphezu kwalokho, ithimba likaProfessor Mi like lenza indlela yokukhulisa i-GaN yekhwalithi ephezulu ku-silicon ukuze kukhule ama-nanowire led ku-silicon. Ngakho-ke, i-µled ihlala ku-Si substrate elungele ukuhlanganiswa nezinye izinto zikagesi ze-CMOS.
Le µled kalula inezinhlelo zokusebenza eziningi ezingaba khona. Iplathifomu yedivayisi izoqina kakhulu njengoba ubude begagasi bokuphuma kwesibonisi se-RGB esihlanganisiwe ku-chip sinwebeka sibebomvu.
Isikhathi sokuthumela: Jan-10-2023