Thaum Lub Kaum Ib Hlis 25th, pab pawg ntawm xibfwb Wei Zhanhua los ntawm Lub Tsev Haujlwm ntawm Luminescent Materials thiab Cov Ntaub Ntawv Qhia ntawm Huaqiao University thiab Lub Tsev Kawm Ntawv ntawm Cov Khoom Siv Science thiab Engineering thiab pab pawg ntawm xibfwb Edward H. Sargent los ntawm Department of Electronic thiab Computer Engineering ntawm University. ntawm Toronto koom ua ke luam tawm ib qho kev tshaj tawm hauv online nyob rau saum toj kawg nkaus thoob ntiaj teb kev kawm phau ntawv journal Nature Research daim ntawv Kev faib tawm tswj ua kom muaj txiaj ntsig zoo txo qis perovskite LEDs. Qhov kev ua haujlwm no tau ua tiav qhov kev txhim kho tseem ceeb hauv kev ua haujlwm thiab kev ua neej nyob ntawm perovskite LED cov khoom siv los ntawm qhov tsis xws luag passivation thiab luminous center dimension tswj, thiab nws yuav tsum tau siv rau cov zaub tshiab thiab teeb pom kev zoo yav tom ntej.
Xwm yog ib qho ntawm cov ntawv xov xwm kev kawm muaj txiaj ntsig tshaj plaws hauv ntiaj teb, mob siab rau tshaj tawm thiab tawm tswv yim txog qhov tseem ceeb tshaj plaws hauv kev tshawb fawb thoob ntiaj teb. Nws yog tsim nyog hais tias nyob rau hauv 2018, Huaqiao University tau luam tawm thawj qhov teeb meem ntawm Xwm raws li ib tug kev sib txuas lus unit thawj zaug. Peb xyoos tom qab, Huaqiao University ib zaug luam tawm Nature' cov ntaub ntawv tseem ceeb raws li chav sib txuas lus, cim tias lub tsev kawm ntawv' qib kev tshawb fawb txog kev tshawb fawb tau txhim kho, thiab nws tau nkag mus rau txoj kab nrawm. ntawm kev noj qab nyob zoo.
Hlau halide perovskites muaj cov khoom zoo heev optoelectronic, xws li siab molar extinction coefficient, ntev cab kuj tsiv mus nyob deb, adjustable band sib txawv, thiab siab tsis xws luag kam rau ua. Lawv muaj kev thov dav dav hauv cov hnub ci hnub ci thiab lub teeb-emitting diodes. Raws li qhov sib txawv ntawm cov qauv siv lead ua microscopic, hlau halide perovskites tuaj yeem muab faib ua xoom-dimensional, qis-dimensional thiab peb-dimensional. Ntawm lawv, cov khoom siv perovskite qis muaj qhov cuam tshuam quantum confinement, muaj lub zog loj exciton khi, tsis yooj yim los tsim cov non-radiative recombination, thiab muaj luminous efficiency.
Txawm li cas los xij, txhawm rau txhim kho kev ua haujlwm siab thiab ruaj khov qis-dimensional hlau halide perovskite cov ntaub ntawv rau cov khoom siv hluav taws xob, tseem muaj ob qhov kev sib tw loj: ua ntej, qhov muaj qhov tsis xws luag yuav ua rau tsim cov chaw uas tsis yog-radiative recombination, ua. mus rau ion migration. Nws yog conducive rau lub luminous efficiency thiab stability ntawm lub cuab yeej; Qhov thib ob yog qhov tsim ntawm ntau theem hybrid quantum qhov dej, uas yuav ua rau lub zog hloov ntawm qhov dav ntawm qhov sib txawv quantum zoo mus rau qhov nqaim band sib txawv quantum zoo nyob rau hauv lub teeb thiab hluav taws xob excitation, uas ua rau dissipation, uas yog tsis conducive rau lub teeb emission. ntawm cov cuab yeej Efficiency, xim purity.
Daim duab 1 Schematic daim duab ntawm zaj duab xis tsim txheej txheem ntawm peb hom perovskite luminescent nyias films, qhov twg PEA sawv cev rau phenethylammonium ntsev, TPPO sawv cev rau triphenylphosphine oxide, thiab TFPPO sawv cev rau tris (4-fluorophenyl) phosphine oxide.
Txhawm rau txhim kho qhov kev ua tau zoo ntawm cov khoom siv hluav taws xob qis perovskite LED, Edward H. Sargent pab pawg ntawm University of Toronto thiab Wei Zhanhua pab pawg ntawm Huaqiao University tau sib koom ua ke thov kom muaj qhov qis-dimensional hlau halide perovskite nto passivation-zoo dav tswj lub tswv yim. Raws li pom nyob rau hauv daim duab 1, thaum lub sij hawm crystallization txheej txheem pib los ntawm anti-solvent, [PbBr6]4-, MA{{7}} thiab Cs{{8}} ions thawj daim ntawv perovskite precursor flakes, thiab ces PEA {{9} } organic cations cuam tshuam nrog cov precursor flakes los tsim cov yeeb yaj kiab uas tsis tshua muaj perovskite luminescence. Hauv pab pawg neeg siv, qhov tsis sib haum xeeb thiab nrawm nrawm ntawm PEA{{11}} cov organic cations coj mus rau tiam ntawm cov chaw tsis xws luag thiab random-dimensional quantum well structures. Hauv pab pawg sim, P = O daim ntawv cog lus hauv TPPO thiab TFPPO cov molecules tuaj yeem cuam tshuam nrog perovskite precursor flakes P = O: Pb2{{14}}, uas tswj cov txheej txheem crystallization thiab txo cov tiam ntawm cov chaw tsis raug. Tsis tas li ntawd, ntau pawg F hauv TFPPO tuaj yeem cuam tshuam nrog PEA+ organic cations kom qeeb qhov kev tso tawm ntawm cov ntaub ntawv raw thiab ncua kev loj hlob ntawm cov muaju, thiab thaum kawg tsim cov yeeb yaj kiab zoo perovskite luminescent nrog qhov ntev ntev.
Daim duab 2 (a) Schematic daim duab ntawm cov qauv ntawm lub perovskite LED ntaus ntawv, cross-sectional kis tau tus mob electron microscope daim duab thiab schematic daim duab ntawm lub zog theem qauv; (b) tam sim no-voltage nkhaus, brightness-voltage nkhaus thiab sab nraud quantum efficiency coj mus rau peb perovskite LED li- Brightness nkhaus; (c) Kev faib tawm ntawm sab nraud quantum efficiency ntawm peb perovskite LED li; (d) Tam sim no-voltage nkhaus ntawm peb perovskite ib leeg-electron thiab ib lub qhov khoom siv; (e) Raws li kev ua TFPPO Lub neej ua haujlwm nkhaus ntawm perovskite LED li.
Raws li pom nyob rau hauv daim duab 2, zaj duab xis no muaj ib tug uniform thiab ntom ntom morphology, nrog ib tug emission wavelength ntawm 517 nm, ib nrab-dav ntawm tsuas yog 20 nm, thiab ib tug photoluminescence efficiency ze rau 100%. Cov khoom siv ntsuab ntsuab tau npaj muaj qhov ua haujlwm sab nraud ntawm 25.6% thiab lub neej ua haujlwm ntawm 2 teev ntawm qhov ci ntawm 7,200 cd m-2, deb tshaj li cov khoom siv zoo sib xws tam sim no tau tshaj tawm.
Xib fwb Wei Zhanhua tau hais tias nyob rau hauv ob peb xyoos dhau los, cov cuab yeej ua haujlwm thiab kev ua haujlwm lub neej ntawm perovskite LEDs tau zoo dua, tab sis tseem muaj txoj hauv kev mus ntev. Nyob rau hauv lub neej yav tom ntej, ntau tus kws tshawb fawb yuav tsum tau ua hauj lwm ua ke los txhim kho qhov ruaj khov-state tso zis kev ua tau zoo, high-efficiency ntaus ntawv repeatability thiab multicolor spectral tso zis kev ua tau zoo ntawm lub cuab yeej.
Nyob rau hauv daim ntawv, Dr. Ma Dongxin, tus kws kho mob tom qab kawm tiav ntawm University of Toronto, yog thawj tus kws sau ntawv. Nws tau ua kev tshawb fawb txog ib xyoos ntawm Huaqiao University; Dr. Kebin Lin los ntawm Huaqiao University yog tus kws sau ntawv thib ob thiab tseem ua haujlwm tseem ceeb hauv kev ua haujlwm. Xib fwb Edward H. Sargent thiab Xib Fwb Wei Zhanhua yog cov kws sau ntawv. Txoj haujlwm tshawb fawb no tau txais kev txhawb nqa los ntawm National Natural Science Foundation ntawm Tuam Tshoj, Natural Science Foundation ntawm Fujian Xeev thiab Kev Tshawb Fawb Txog Kev Tshawb Fawb ntawm Huaqiao University. (
