I-LED yendabuko ishintshe kakhulu insimu yokukhanyisa nokubonisa ngenxa yokusebenza kwayo okuphezulu maqondana nokusebenza kahle, ukuzinza kanye nosayizi wedivayisi. Ama-LED ngokuvamile ayizinqwaba zamafilimu amancane e-semiconductor anezilinganiso ezisemaceleni zamamilimitha, amancane kakhulu kunamadivayisi endabuko afana nama-incandescent bulbs nama-cathode tubes. Kodwa-ke, izinhlelo zokusebenza ze-optoelectronic ezisafufusa, njenge-virtual kanye ne-augmented reality, zidinga ama-LED ngobukhulu bama-micron noma ngaphansi. Ithemba liwukuthi ama-LED (µleds) amancane noma angaphansi kwe-submicron scale aqhubeka nokuba nezimfanelo eziningi ezinhle kakhulu ama-LED endabuko asenazo kakade, njengokukhipha okuzinzile kakhulu, ukusebenza kahle okuphezulu nokukhanya, ukusetshenziswa kwamandla okuphansi kakhulu, kanye nokukhipha okugcwele umbala, kuyilapho ecishe abe mancane ngokuphindwe kasigidi endaweni, okuvumela ukubonisa okufushane kakhulu. Ama-chip e-LED anjalo angavula indlela yamasekethe e-photonic anamandla kakhulu uma engakhuliswa nge-single-chip ku-Si futhi ahlanganiswe nama-electronics e-complementary metal oxide semiconductor (CMOS).
Kodwa-ke, kuze kube manje, ama-µled anjalo awakatholakali, ikakhulukazi ebangeni lobude be-wavelength oluluhlaza kuya kobomvu. Indlela yendabuko ye-led µ-led iyinqubo ephezulu lapho amafilimu e-InGaN quantum well (QW) aqoshwa khona kumadivayisi amancane ngenqubo yokuqopha. Ngenkathi ama-tio2 µled e-InGaN QW asekelwe ku-thin-film adonsele ukunaka okukhulu ngenxa yezakhiwo eziningi ezinhle ze-InGaN, njengokuthuthwa kwenkampani okusebenzayo kanye nokulungiswa kwe-wavelength kulo lonke ububanzi obubonakalayo, kuze kube manje abe nezinkinga ezifana nomonakalo wokugqwala kodonga oluseceleni oqhubeka uba mubi njengoba usayizi wedivayisi uncipha. Ngaphezu kwalokho, ngenxa yokuba khona kwamasimu e-polarization, anokungazinzile kwe-wavelength/color. Kule nkinga, kuphakanyiswe izixazululo ze-InGaN ezingezona i-polar kanye ne-semi-polar kanye ne-photonic crystal cavity, kodwa azanelisi okwamanje.
Ephepheni elisha elishicilelwe ku-Light Science and Applications, abacwaningi abaholwa nguZetian Mi, uprofesa eNyuvesi yaseMichigan, u-Annabel, bathuthukise i-submicron green LED iii – nitride enqoba lezi zithiyo unomphela. Lawa ma-µled enziwe yi-epitaxy ye-molecular beam esetshenziswa yi-plasma. Ngokuphambene kakhulu nendlela yendabuko yokuphuma phezulu, i-µled lapha iqukethe izintambo eziningi, ngayinye inobubanzi obuyi-100 kuya ku-200 nm kuphela, ehlukaniswe ngama-nanometer angamashumi. Le ndlela yokuphuma phansi iye phezulu empeleni igwema umonakalo wokugqwala kodonga oluseceleni.
Ingxenye ekhipha ukukhanya yale divayisi, eyaziwa nangokuthi isifunda esisebenzayo, yakhiwe ngezakhiwo ze-core-shell multiple quantum well (MQW) ezibonakala ngesimo se-nanowire. Ikakhulukazi, i-MQW iqukethe umthombo we-InGaN kanye nomgoqo we-AlGaN. Ngenxa yokwehluka kokufuduka kwe-athomu okufakwe yi-Group III elements indium, gallium kanye ne-aluminium ezindongeni eziseceleni, sithole ukuthi i-indium yayingekho ezindongeni eziseceleni ze-nanowires, lapho igobolondo le-GaN/AlGaN ligoqa khona umongo we-MQW njenge-burrito. Abacwaningi bathole ukuthi okuqukethwe kwe-Al kwaleli gobolondo le-GaN/AlGaN kwehla kancane kancane kusukela ohlangothini lokujova kwama-electron lwe-nanowires kuya ohlangothini lokujova imbobo. Ngenxa yokwehluka emasimini okujova kwangaphakathi kwe-GaN kanye ne-AlN, i-gradient enjalo yokuqukethwe kwe-Al kusendlalelo se-Al idala ama-electron amahhala, okulula ukugeleza kuwo umongo we-MQW futhi kunciphise ukungazinzi kombala ngokunciphisa insimu yokujova.
Eqinisweni, abacwaningi bathole ukuthi kumadivayisi angaphansi kwe-micron eyodwa ububanzi, ubude be-wavelength ye-electroluminescence, noma ukukhishwa kokukhanya okubangelwa ugesi, kuhlala kungaguquki ngokulandelana kokushintsha kokujova kwamanje. Ngaphezu kwalokho, ithimba likaProfesa Mi selisungule indlela yokukhulisa izembozo ze-GaN ezisezingeni eliphezulu ku-silicon ukuze kukhuliswe ama-nanowire LED ku-silicon. Ngakho-ke, i-µled ihlala ku-substrate ye-Si ilungele ukuhlanganiswa nezinye izinto ze-elekthronikhi ze-CMOS.
Le µled inezinhlelo zokusebenza eziningi ezingaba khona. Ipulatifomu yedivayisi izoqina kakhulu njengoba ubude bokukhanya kokukhishwa kwesibonisi se-RGB esihlanganisiwe ku-chip bukhula bube bomvu.
Isikhathi sokuthunyelwe: Jan-10-2023