LED yachikhalidwe yasintha gawo la kuyatsa ndikuwonetsa chifukwa chakuchita bwino kwambiri, kukhazikika komanso kukula kwa chipangizocho. Ma LED nthawi zambiri amakhala filimu yopyapyala ya semiconductor yokhala ndi miyeso yakutsogolo ya mamilimita, yaying'ono kwambiri kuposa zida zakale monga mababu a incandescent ndi machubu a cathode. Komabe, ntchito za optoelectronic zomwe zikubwera, monga zenizeni ndi zowonjezereka, zimafuna ma LED a kukula kwa ma microns kapena ocheperapo. Chiyembekezo ndi chakuti ma micro - kapena submicron scale LED (µleds) akupitiriza kukhala ndi makhalidwe apamwamba omwe ma LED ali nawo kale, monga kutulutsa kosasunthika, kuyendetsa bwino komanso kuwala, kugwiritsa ntchito mphamvu zochepa kwambiri, komanso kutulutsa mitundu yonse, pomwe imakhala yaying'ono nthawi miliyoni m'derali, kulola zowonetsera zambiri. Tchipisi zotsogola zotere zithanso kutsegulira njira zozungulira zamphamvu kwambiri ngati zitha kukulira chip-chimodzi pa Si ndikuphatikizidwa ndi zamagetsi zamagetsi zachitsulo cha oxide semiconductor (CMOS).
Komabe, mpaka pano, ma µleds oterowo akhalabe osowa, makamaka mumtundu wobiriwira mpaka wofiyira wotulutsa wavelength. Njira yachikhalidwe yotsogozedwa ndi µ ndi njira yopita pamwamba pomwe makanema a InGaN quantum well (QW) amasanjidwa kukhala zida zazing'ono kudzera munjira yolumikizira. Ngakhale filimu yopyapyala ya InGaN QW yochokera ku tio2 µleds yakopa chidwi kwambiri chifukwa cha zinthu zambiri zabwino kwambiri za InGaN, monga zonyamulira zonyamulira komanso kusinthasintha kwa mafunde pamitundu yonse yowoneka, mpaka pano akhala akuvutitsidwa ndi zinthu monga khoma lakumbali. kuwonongeka kwa dzimbiri komwe kumakulirakulira pamene kukula kwa chipangizo kukucheperachepera. Kuphatikiza apo, chifukwa cha kukhalapo kwa minda ya polarization, amakhala ndi kutalika kwa mafunde / mtundu. Pa vutoli, njira zopanda polar ndi semi-polar InGaN ndi photonic crystal cavity zothetsera zaperekedwa, koma sizokhutiritsa pakali pano.
Mu pepala latsopano lofalitsidwa mu Light Science and Applications, ofufuza motsogoleredwa ndi Zetian Mi, pulofesa wa yunivesite ya Michigan, Annabel, apanga submicron scale green LED iii - nitride yomwe imagonjetsa zopingazi kamodzi kokha. Ma µled awa adapangidwa ndi ma epitaxy omwe amathandizidwa ndi plasma. Mosiyana kwambiri ndi njira yachikhalidwe yopita pansi, µled apa imakhala ndi ma nanowires, iliyonse 100 mpaka 200 nm m'mimba mwake, yolekanitsidwa ndi makumi a nanometers. Njira yopita pansiyi imapewa kuwonongeka kwa khoma lakumbuyo.
Mbali yotulutsa kuwala ya chipangizocho, yomwe imadziwikanso kuti dera logwira ntchito, imapangidwa ndi core-shell multiple quantum well (MQW) yodziwika ndi nanowire morphology. Makamaka, MQW imakhala ndi chitsime cha InGaN ndi chotchinga cha AlGaN. Chifukwa cha kusiyana kwa adsorbed atomu kusamuka kwa Gulu III zinthu indium, gallium ndi zotayidwa pa makoma mbali, tinapeza kuti indium anali kusowa pa mbali makoma a nanowires, kumene GaN / AlGaN chipolopolo atakulungidwa MQW pachimake ngati burrito. Ofufuzawa adapeza kuti Al zomwe zili mu chipolopolo cha GaN / AlGaN zidatsika pang'onopang'ono kuchokera kumbali ya jakisoni wa ma elekitironi wa nanowires kupita kumbali ya jekeseni wa dzenje. Chifukwa cha kusiyana kwa magawo a polarization amkati a GaN ndi AlN, kuchuluka kwa ma voliyumu a Al mu gawo la AlGaN kumapangitsa ma elekitironi aulere, omwe ndi osavuta kulowa mkati mwa MQW ndikuchepetsa kusakhazikika kwa utoto pochepetsa gawo la polarization.
M'malo mwake, ofufuzawo apeza kuti pazida zosakwana micron imodzi m'mimba mwake, kutalika kwa mafunde a electroluminescence, kapena kutulutsa kuwala komwe kumachitika pakalipano, kumakhalabe kosasintha malinga ndi kuchuluka kwa kusintha kwa jakisoni wapano. Kuphatikiza apo, gulu la Pulofesa Mi lidapangapo kale njira yokulitsa zokutira zamtundu wapamwamba wa GaN pa silicon kuti zikule ma LED a nanowire pa silicon. Chifukwa chake, µled imakhala pagawo la Si lokonzekera kuphatikizidwa ndi zamagetsi zina za CMOS.
Izi µled mosavuta zimakhala ndi mapulogalamu ambiri. Pulatifomu ya chipangizocho idzakhala yolimba kwambiri pomwe mawonekedwe amtundu wa RGB wophatikizidwa pa chip akufutukuka kukhala ofiira.
Nthawi yotumiza: Jan-10-2023