Tau qhov twg los: news.mit.edu
Perovskites tuav cov lus cog tseg rau kev tsim cov hnub ci vaj huam sib luag uas tuaj yeem yooj yim tso rau ntau qhov chaw, suav nrog cov hloov tau yooj yim thiab textured. Cov ntaub ntawv no kuj yuav yog lub teeb yuag, pheej yig los tsim, thiab muaj txiaj ntsig zoo li niaj hnub no cov khoom siv hluav taws xob photovoltaic, uas feem ntau yog silicon. Lawv yog cov ntsiab lus ntawm kev tshawb fawb thiab kev nqis peev ntxiv, tab sis cov tuam txhab nrhiav kev siv lawv lub peev xwm yuav tsum tau daws qee qhov kev nyuaj siab ua ntej perovskite-based solar cells tuaj yeem ua lag luam sib tw.
Lub sij hawm perovskite tsis yog hais txog cov khoom siv tshwj xeeb, xws li silicon lossis cadmium telluride, lwm cov kev sib tw hauv lub ntiaj teb photovoltaic, tab sis rau tag nrho tsev neeg ntawm cov tebchaw. Perovskite tsev neeg ntawm cov ntaub ntawv hnub ci yog lub npe rau nws cov qauv zoo sib xws rau cov ntxhia hu ua perovskite, uas tau pom nyob rau hauv 1839 thiab muaj npe tom qab Lavxias teb sab mineralogist LA Perovski.
Tus thawj pob zeb hauv av perovskite, uas yog calcium titanium oxide (CaTiO3), muaj qhov sib txawv siv lead ua. Nws muaj peb feem qauv, uas nws cov khoom tau los sau npe A, B thiab X, nyob rau hauv uas lattices ntawm cov khoom sib txawv yog interlaced. Cov tsev neeg ntawm perovskites muaj ntau qhov sib xyaw ua ke ntawm cov ntsiab lus lossis cov molecules uas tuaj yeem tuav txhua yam ntawm peb yam thiab tsim cov qauv zoo ib yam li cov thawj perovskite nws tus kheej. (Qee cov kws tshawb fawb txawm khoov cov cai me ntsis los ntawm kev naming lwm cov qauv siv lead ua nrog cov ntsiab lus zoo sib xws "perovskites," txawm hais tias qhov no yog frowned los ntawm crystallographers.)
"Koj tuaj yeem sib tov thiab sib xyaw cov atoms thiab cov molecules rau hauv cov qauv, nrog qee qhov txwv. Piv txwv li, yog tias koj sim ua cov khoom molecule uas loj dhau rau hauv cov qauv, koj yuav distort nws. Thaum kawg koj yuav ua rau 3D siv lead ua cais rau hauv. ib tug 2D txheej txheej, los yog poob cov qauv tag nrho, "hais tias Tonio Buonassisi, tus xibfwb ntawm mechanical engineering ntawm MIT thiab tus thawj coj ntawm Photovoltaics Research Laboratory. "Perovskites yog cov tunable heev, zoo li tsim-koj-tus kheej-kev lom zem hom siv lead ua qauv," nws hais.
Cov qauv ntawm interlaced lattices muaj cov ions los yog them cov molecules, ob ntawm lawv (A thiab B) zoo them thiab lwm tus (X) tsis zoo them. A thiab B ions feem ntau yog qhov sib txawv heev, nrog rau A yog loj dua.
Nyob rau hauv tag nrho cov qeb ntawm perovskites, muaj ntau ntau hom, xws li hlau oxide perovskites, uas tau pom daim ntawv thov nyob rau hauv catalysis thiab nyob rau hauv lub zog cia thiab hloov dua siab tshiab, xws li nyob rau hauv roj hlwb thiab hlau-air roj teeb. Tab sis lub ntsiab tseem ceeb ntawm kev tshawb fawb kev ua haujlwm rau ntau tshaj kaum xyoo tau ua rau cov hlau lead halide perovskites, raws li Buonassisi hais.
Nyob rau hauv pawg ntawd, tseem muaj ib pab pawg ntawm cov muaj peev xwm, thiab cov chaw sim thoob ntiaj teb tab tom sib tw los ntawm kev ua haujlwm nyuaj ntawm kev sim nrhiav cov kev hloov pauv uas qhia txog qhov ua tau zoo tshaj plaws hauv kev ua haujlwm, nqi, thiab kav ntev - uas tau dhau los ua qhov nyuaj tshaj plaws. ntawm peb.
Ntau pab pawg kuj tau tsom mus rau cov kev hloov pauv uas tshem tawm kev siv cov hmoov txhuas, kom tsis txhob muaj kev cuam tshuam ib puag ncig. Buonassisi sau tseg, txawm li cas los xij, tias "raws li lub sijhawm, cov khoom siv lead-raws li txuas ntxiv txhim kho hauv lawv qhov kev ua tau zoo, thiab tsis muaj lwm yam kev sib xyaw ua ke tau ze ntawm kev ua haujlwm hauv hluav taws xob." Kev ua haujlwm txuas ntxiv mus tshawb nrhiav lwm txoj hauv kev, tab sis tam sim no tsis muaj leej twg tuaj yeem sib tw nrog cov hlau lead halide versions.
Ib qho txiaj ntsig zoo ntawm perovskites muab yog lawv lub siab ntev ntawm qhov tsis xws luag hauv cov qauv, nws hais. Tsis zoo li silicon, uas yuav tsum tau muaj siab purity ua haujlwm zoo hauv cov khoom siv hluav taws xob, perovskites tuaj yeem ua haujlwm zoo txawm tias muaj ntau yam tsis zoo thiab tsis huv.
Kev tshawb nrhiav kev cog lus tshiab cov neeg sib tw sib xyaw ua ke rau perovskites yog me ntsis zoo li nrhiav ib rab koob hauv haystack, tab sis tsis ntev los no cov kws tshawb fawb tau los nrog lub tshuab kev kawm uas tuaj yeem txhim kho cov txheej txheem no. Txoj hauv kev tshiab no tuaj yeem ua rau muaj kev txhim kho sai dua ntawm lwm txoj hauv kev tshiab, hais tias Buonassisi, uas yog tus kws sau ntawv ntawm qhov kev tshawb fawb ntawd.
Thaum perovskites tseem qhia tau cov lus cog tseg zoo, thiab ntau lub tuam txhab tau npaj los pib qee qhov kev lag luam, kev ua haujlwm ntev tseem yog qhov teeb meem loj tshaj plaws uas lawv ntsib. Thaum silicon hnub ci vaj huam sib luag khaws cia txog li 90 feem pua ntawm lawv cov hluav taws xob tso zis tom qab 25 xyoo, perovskites degrade sai dua. Kev ua tau zoo tau ua tiav - cov qauv pib tsuas yog siv sijhawm li ob peb teev, tom qab ntawd lub lis piam lossis ntau lub hlis, tab sis cov qauv tshiab tau siv tau ntev txog li ob peb xyoos, tsim nyog rau qee cov ntawv thov uas tsis muaj qhov tseem ceeb.
Los ntawm kev tshawb fawb pom, Buonassisi hais tias, ib qho txiaj ntsig ntawm perovskites yog tias lawv yooj yim ua hauv chav kuaj - cov tshuaj lom neeg sib sau ua ke tau yooj yim. Tab sis qhov ntawd kuj yog lawv cov downside: "Cov khoom mus ua ke yooj yim heev ntawm chav tsev kub," nws hais tias, "tab sis nws kuj tuaj sib nrug yooj yim heev ntawm chav tsev kub. Yooj yim los, yooj yim mus!"
Txhawm rau daws qhov teeb meem ntawd, feem ntau cov kws tshawb fawb tau tsom mus rau kev siv ntau yam khoom siv tiv thaiv los thaiv cov perovskite, tiv thaiv nws los ntawm huab cua thiab ya raws. Tab sis lwm tus tab tom kawm txog cov txheej txheem tseeb uas ua rau qhov kev puas tsuaj, hauv kev cia siab ntawm kev nrhiav cov qauv lossis kev kho mob uas muaj zog dua. Qhov kev tshawb pom tseem ceeb yog qhov txheej txheem hu ua autocatalysis yog qhov ua txhaum loj rau kev tawg.
Nyob rau hauv autocatalysis, sai li sai tau raws li ib feem ntawm cov khoom pib degrade, nws cov tshuaj tiv thaiv cov khoom ua raws li catalysts pib degrading cov nyob sib ze qhov chaw ntawm cov qauv, thiab ib tug runaway cov tshuaj tiv thaiv tau pib. Ib qho teeb meem zoo sib xws muaj nyob rau hauv kev tshawb fawb thaum ntxov ntawm qee yam khoom siv hluav taws xob, xws li cov organic teeb-emitting diodes (OLEDs), thiab nws thiaj li daws tau los ntawm kev ntxiv cov txheej txheem purification ntxiv rau cov khoom siv raw, yog li cov kev daws teeb meem zoo sib xws tuaj yeem pom nyob rau hauv rooj plaub. perovskites, Buonassisi qhia.
Buonassisi thiab nws cov kws tshawb fawb sib koom ua ke tsis ntev los no tau ua tiav txoj kev tshawb fawb qhia tias ib zaug perovskites ncav cuag lub neej siv tau tsawg kawg yog kaum xyoo, ua tsaug rau lawv cov nqi pib qis dua uas yuav txaus los ua kom lawv muaj txiaj ntsig zoo los hloov cov silicon hauv cov khoom siv loj, cov nqi hluav taws xob- scale hnub ci ua liaj ua teb.
Zuag qhia tag nrho, kev nce qib hauv kev txhim kho ntawm perovskites tau ua tau zoo thiab txhawb nqa, nws hais. Tsuas yog ob peb xyoos ntawm kev ua haujlwm, nws twb tau ua tiav cov txiaj ntsig zoo piv rau qib uas cadmium telluride (CdTe), "uas tau nyob ib puag ncig ntev dua, tseem tab tom tawm tsam kom ua tiav," nws hais. "Qhov yooj yim uas cov kev ua tau zoo dua no tau mus txog hauv cov khoom tshiab no yuav luag stupefying." Sib piv cov sij hawm tshawb fawb siv los ua kom tiav 1 feem pua ntawm kev txhim kho kev ua tau zoo, nws hais tias, kev nce qib ntawm perovskites tau nyob ntawm qhov chaw nruab nrab ntawm 100 thiab 1, 000 npaug sai dua li ntawm CdTe. "Qhov ntawd yog ib qho laj thawj uas nws zoo siab heev," nws hais.
