Txawm hais tias muaj kev txhim kho sai ntawm lub teeb-emitting diodes (LEDs) raws li qhov tshwm sim perovskite nanocrystals (PENCs), nws tseem nyuaj kom ua tiav kev sib xyaw ua haujlwm siab -kev ua tau zoo thiab siab- cov khoom siv ci ntsa iab vim cov insulating ntev - saw ligands siv los ntawm PENCs.
Ntawm no, cov kws tshawb fawb los ntawm UESTC thiab lwm chav tsev tau tsim cov luminescent thiab ruaj khov formamidine lead bromide PENCs, capped nrog rationally tsim 2-naphthalenesulfonic acid (NSA) luv luv aromatic ligands, siv nyob rau hauv LEDs. Piv nrog rau feem ntau siv oleic acid ligands, NSA molecules tsis tsuas yog tuav cov khoom saum npoo ntawm PENS thaum lub sij hawm purification, tab sis kuj tseem txhim kho cov khoom hluav taws xob ntawm cov txheej txheem sib sau ua ke, kom ntseeg tau cov nqi txhaj tshuaj / thauj hauv lub cuab yeej. Lub electroluminescence ntawm qhov ua tau zoo tshaj plaws LED qhia tau hais tias lub siab ci ntawm 67115 cd cm-2 thiab lub ncov sab nraud quantum efficiency ntawm 19.2 feem pua.
The related paper was published in the journal ACS Energy Letters with the title "High-Brightness Perovskite Light-Emitting Diodes Based on FAPbBr3 Nanocrystals with Rationally Designed Aromatic Ligands".
Hlau halide perovskite nanocrystals (PENCs) tsis ntev los no tau tshwm sim los ua cov neeg sib tw rau qis- nqi, siab- lub teeb ua tau zoo- emitting diodes (LEDs). High-PENCs zoo nrog ze-unit luminescence quantum yield (PLQY) tuaj yeem tau txais nyob rau hauv cov xwm txheej sib xyaw me me vim lawv qhov tsis xws luag siab heev- cov cuab yeej kam rau ua. Tsis tas li ntawd, lub teeb emissions ntawm PENCs nthuav tawm dav tunability thiab nqaim emission linewidth hla tag nrho cov pom spectrum, uas ua rau muaj ultra- xim gamut dav npog txog 100 feem pua. Qhov no ua rau nws yog tus neeg sib tw zoo tshaj plaws rau siab - daws teeb meem cov ntawv thov.
Hauv ob peb xyoos dhau los, nrog rau kev tshawb fawb dav dav ntawm cov khoom sib txuas thiab qhov chaw passivation ntawm PENCs, sab nraud quantum efficiency (EQE) ntawm cov LEDs cuam tshuam tau nce sai ntawm kwv yees li ntawm 0.1 feem pua rau cov nqi siab ntawm ntau dua 20 feem pua. , uas yog piv rau kev lag luam luminescence technologies. Txawm hais tias muaj kev vam meej hauv kev paub txog PENS-raws li siab- LEDs ua haujlwm tau zoo, feem ntau lub xeev- ntawm-- cov khoom siv kos duab tsis tshua muaj qhov system{{8 }} kev sib xyaw ua ke siab EQE thiab siab ci ntsa iab. Qhov no feem ntau yog txwv los ntawm cov nqi them tsis zoo / kev thauj mus los hauv lub cuab yeej, uas yog los ntawm cov khoom siv hluav taws xob ntawm cov kab hluav taws xob ntev -chain organic ligands feem ntau siv hauv PENCs.
Txhawm rau kho cov khoom nto ntawm PENCs, ntxiv rau cov khoom siv ntev ntev -chain oleylamine thiab oleic acid (OA), cov txheej txheem ntawm lwm cov ligands tau tshawb nrhiav thiab ntau qhov tseem ceeb tshaj tawm -synthesis ligand tswj cov tswv yim tau tsim kho. Txawm li cas los xij, vim yog cov ligand ruaj khov heev thiab cov qauv siv lead ua ionic ntawm perovskites, cov khoom nto thiab cov qauv kev ncaj ncees ntawm PENCs yog cov rhiab heev rau ib puag ncig tshuaj lom neeg thaum lub sij hawm colloidal synthesis thiab post- ua, uas ua rau lub realization ntawm rational. ligand engineering ntawm PENCs siab heev. nyuaj. Yog li ntawd, tsim nyog nto ligands uas muaj peev xwm tswj tau lub siab luminous efficiency thiab zoo heev colloidal stability ntawm PENCs, thaum ua kom lub zog hluav taws xob zoo ntawm lub resulting emissive txheej, yog ib qho tseem ceeb rau yav tom ntej kev ua tau zoo ntawm cov LEDs.
Hauv kev ua haujlwm no, cov kws sau ntawv tau tshaj tawm qhov siab {{{0}}} ci ntsa iab, siab - ua haujlwm tau zoo LED raws li cov ntshiab ntsuab- emitting lead formamidine bromide (FAPbBr3), nthuav tawm ligand pauv thiab / lossis PENS cov nyiaj them thaum lub sijhawm ua kom huv si siv NSA- muaj cov kuab tshuaj, yog li txhim kho qhov ruaj khov ntawm cov tshuaj colloidal thiab PLQYs siab. Tsis tas li ntawd, cov khaubncaws sab nraud povtseg ntawm NSA PECs qhia cov khoom thauj zoo, uas tuaj yeem tshwm sim los ntawm kev sib txuas muaj zog ntawm PECs induced los ntawm NSA molecules. Los ntawm embedding ib tug optimized NSA FAPbBr3 emitter rau hauv ib tug ua tiav LED, cov cuab yeej nthuav tawm ib tug ntsuab electroluminescence (EL) ncov ntawm 532 nm nrog ib nrab - qhov siab dav (fwhm) ntawm kwv yees li 21 nm, sib xws rau International Commission on Illumination (CIE) ua haujlwm (0.19,0.77), lub ntsiab xim ntsuab.
Fig.1 Material synthesis thiab characterization
Daim duab 2 Ligand binding zog ntawm PENCs
Daim duab 3 Ib leeg- cov yam ntxwv ntawm tus neeg nqa khoom
Daim duab 4 LEDs raws li FAPbBr3 perovskite nanocrystals
