Source: sciencedaily
Ib tug neeg tshawb fawb ntawm Georgia Tech tuav ib lub nruab hnub hauv lub nruab hnub, uas yog hloov tau thiab sib zog dua cov twj raws li silicon.
Credit: Rob Felt, Georgia Tech
Muaj ntau yam nyiam txog perbergite-raws li hnub ci lub hlwb. Lawv yog cov yooj yooj yim thiab pheej yig los tsim, muaj kev yooj yim uas yuav qhib ntau txoj kev ntawm txoj kev txhim kho thiab cov chaw, thiab nyob rau hauv xyoo tas los no tau mus txog cov hauj lwm hluav taws xob cov kev coj ua ntawm cov kev cai ntawm silicon-based hlwb.
Tiam sis xam pom tias yuav ua li cas tsim cov khoom siv hluav taws xob raws li lub sijhawm ntev tshaj ob peb lub hlis lawm.
Tam sim no cov neeg tshawb fawb los ntawm Georgia lub Tsev Kawm Ntawv ntawm Kev Tshawb Fawb, University of California San Diego thiab Massachusetts Institute of Technology tau tshaj tawm txog kev tshawb pom tshiab txog perovskite hnub ci hlwb uas yuav ua rau txoj kev ua kom zoo dua.
"Perovskite solar cells muab ntau ntawm cov kev zoo dua vim tias lawv yog cov tsis tshua muaj hnav thiab ua tau yooj yim nrog cov khoom yooj yim," said Juan-Pablo Correa-Baena, tus pab xibfwb hauv Georgia Tech School of Materials Science thiab Engineering. "Yuav tsum tau sib tw ua lag luam nyob rau hauv kev lag luam nrog silicon-based solar cells, txawm li cas los, lawv yuav tsum tau ua ntau dua."
Nyob rau hauv kev tshawb nrhiav uas luam tawm Lub Ob Hlis 8 nyob rau hauv phau ntawv sau Science thiab yog txhawb nqa los ntawm US Department Energy thiab National Science Foundation, cov kws tshawb fawb tau piav qhia txog cov tswv yim txog kev ntxiv ntshav alkali hlau rau cov tshuaj perovskites ua rau kev ua tau zoo dua.
"Perovskites yuav hloov qhov kev ua si hauv hnub ci," said David Fenning, ib tug xib fwb ntawm nanoengineering nyob hauv University of California San Diego. "Lawv muaj peev xwm txo cov nqi tsis txo kev ua haujlwm, tiam sis tseem muaj ntau yam tseem ceeb kawm txog cov ntaub ntawv no."
Yuav kom to taub perovskite muaju, nws yuav pab tau yog xav txog nws cov qauv crystalline raws li ib tug triad. Ib feem ntawm lub triad yog li tsim los ntawm cov hlau lead. Qhov thib ob yog feem ntau ua los ntawm cov organic feem xws li methylammonium, thiab tus thib peb feem ntau yog ua los ntawm lwm yam halides xws li bromine thiab iodine.
Hauv cov xyoo dhau los, cov neeg tshawb nrhiav tau soj ntsuam cov zaub mov txawv kom ua tau zoo dua qub, xws li ntxiv iodine thiab bromine rau cov hlau lead hauv tus qauv. Tom qab ntawd, lawv sim hloov cesium thiab rubidium mus rau ib feem ntawm perovskite feem ntau nyob ntawm cov organic molecules.
"Peb paub los ntawm kev ua hauj lwm yav dhau los uas ntxiv cesium thiab rubidium rau ib qho kev sib xyaw ua bromine thiab iodine lead perovskite ua rau kom muaj kev ruaj ntseg zoo dua thiab ua tau zoo dua," Correa-Baena said.
Tab sis me ntsis twb paub txog yog vim li cas ntxiv cov alkali hlau txhim kho kev kawm ntawm peršiites.
Yuav kom nkag siab tias yog vim licas thiaj li ua haujlwm, cov kws tshawb fawb tau siv xoo hluav taws xob xav los kuaj xyuas cov perbergites ntawm nanoscale.
"Raws li saib hauv cov ntaub ntawv hauv perovskite cov khoom, peb tuaj yeem pom tau hais tias txhua tus neeg ua haujlwm yog qhov zoo tshaj plaws hauv kev txhim kho kev ua haujlwm," said Yanqi (Grace) Luo, tus nanoengineering PhD ntawm UC San Diego.
Lawv nrhiav pom tias thaum lub cesium thiab rubidium tau ntxiv rau cov xyaw bromine thiab iodine lead perovskite, nws ua rau tus bromine thiab iodine sib tov ua ke ntau homogeneously, uas ua kom muaj li 2 feem pua siab dua efficiency dua cov khoom tsis muaj cov khoom ntxiv.
"Peb pom tias uniformity hauv chemistry thiab tus qauv yog dab tsi pab ib perbergite solar cell khiav ntawm nws cov peev xwm uas muaj peev xwm tshaj plaws," Fenning said. "Txhua qhov chaw nyob hauv qhov pob txig yog zoo li qhov tsis muaj zog nyob hauv cov saw hlau."
Txawm li ntawd los, cov neeg tshawb xyuas tseem pom tias thaum rubidium los yog cesium ua rau tus bromine thiab iodine tuaj yeem ua homogenous, cov pa taws lawv tus kheej nyob rau hauv lawv tus kheej cov ntaub ntawv tseem nyob ruaj khov, ua rau cov "tsis tuag" nyob rau hauv lub hnub ci uas tsis tsim.
"Qhov no yog ib qho txawv heev," Fenning tau hais. "Nyob hauv lwm cov ntaub ntawv, lawv ua yam xws li dub qhov uas nqus hauv electrons los ntawm lwm thaj chaw thiab tsis txhob cia lawv mus, yog li koj poob tam sim no thiab qhov hluav taws xob.
"Tiam sis hauv cov perbergites, peb pom hais tias cov chaw tuag nyob ib ncig ntawm rubidium thiab cesium tsis raug dejnum rau hnub ci kev ua haujlwm ntawm lub computer, tab sis muaj qee qhov poob," Fenning said. "Qhov no qhia tau hais tias cov ntaub ntawv ua tau zoo npaum li cas tiam sis tseem muaj ntau txoj kev txhim kho ntxiv."
Cov kev tshawb pom ntxiv rau qhov kev nkag siab txog kev siv cov perbergite raws li kev ua haujlwm ntawm lub nanoscale thiab tuaj yeem ua haujlwm hauv kev txhim kho rau yav tom ntej.
"Cov ntaub ntawv cog lus cog lus tias yuav ua tau zoo heev thiab ua tau zoo, uas yog zoo nkauj npaum li cas peb xav tau kom paub tseeb tias cov photovoltaic panels deployed dav," Correa-Baena said. "Peb xav sim kom offset cov teeb meem ntawm kev nyab xeeb kev hloov, yog li lub tswv yim yog muaj photovoltaic hlwb uas pheej yig li sai tau."
