{"id":5388,"date":"2022-04-08T15:35:21","date_gmt":"2022-04-08T13:35:21","guid":{"rendered":"https:\/\/www.enviblog.cz\/blog\/?p=5388"},"modified":"2022-04-08T15:35:21","modified_gmt":"2022-04-08T13:35:21","slug":"perovskity-nadeje-pro-fotovoltaiku-ii-dil","status":"publish","type":"post","link":"https:\/\/www.enviblog.cz\/blog\/2022\/04\/08\/perovskity-nadeje-pro-fotovoltaiku-ii-dil\/","title":{"rendered":"Perovskity-nad\u011bje pro fotovoltaiku? \u2013 II. d\u00edl"},"content":{"rendered":"

V\u00a0minul\u00e9 \u010d\u00e1sti jsme si nast\u00ednili, co to vlastn\u011b fotovoltaika je a jak funguj\u00ed fotovoltaick\u00e9 \u010dl\u00e1nky. Narazili jsme u toho na jeden fyzik\u00e1ln\u00ed limit, a to teoretickou hranici \u00fa\u010dinnosti p\u0159em\u011bny slune\u010dn\u00ed energie na energii elektrickou, kter\u00e1 se nap\u0159\u00edklad pro k\u0159em\u00edkov\u00e9 \u010dl\u00e1nky pohybuje m\u00edrn\u011b nad 30 %. Co si budeme nalh\u00e1vat, vzhledem k\u00a0tomu, \u017ee v\u00a0praxi se dosahuje \u00fa\u010dinnost\u00ed je\u0161t\u011b ni\u017e\u0161\u00edch (doch\u00e1z\u00ed toti\u017e k\u00a0energetick\u00fdm ztr\u00e1t\u00e1m), cel\u00e9 fotovoltaice tento fakt docela ub\u00edr\u00e1 na kr\u00e1se. Nedalo by se s t\u00edm p\u0159eci jen n\u011bco d\u011blat? Odpov\u011b\u010f by n\u00e1m mohly d\u00e1t perovskity. K\u0159em\u00edkov\u00fdm fotovoltaick\u00fdm \u010dl\u00e1nk\u016fm toti\u017e trvalo asi 60 let, ne\u017e se u nich doc\u00edlilo \u00fa\u010dinnosti 25 %, perovskitov\u00fdm fotovoltaick\u00fdm \u010dl\u00e1nk\u016fm na to sta\u010dilo n\u011bco m\u00e1lo p\u0159es 10 let.<\/p>\n

Co to tedy ty podivn\u011b zn\u011bj\u00edc\u00ed perovskity jsou? Jedn\u00e1 se o pom\u011brn\u011b \u0161irokou skupinu slou\u010denin odvozen\u00fdch od miner\u00e1lu perovskitu (chemicky se jedn\u00e1 o oxid titani\u010dito-v\u00e1penat\u00fd, \u00a0CaTiO3<\/sub>). Tento miner\u00e1l byl poprv\u00e9 objeven a pops\u00e1n n\u011bmeck\u00fdm mineralogem Gustavem Rosem v\u00a0roce 1839 b\u011bhem jeho cesty poho\u0159\u00edm Ural. Pojmenoval jej po rusk\u00e9m mineralogovi, diplomatovi Lvu Perovsk\u00e9m (ten dokonce sv\u00e9ho \u010dasu p\u016fsobil jako ministr vnitra na dvo\u0159e cara Mikul\u00e1\u0161e I.) Obecn\u00fd vzorec t\u00e9to skupiny l\u00e1tek je ABX3<\/sub>, kde A, B p\u0159edstavuj\u00ed kationty (kladn\u011b nabit\u00e9 ionty), X p\u0159edstavuje aniont (z\u00e1porn\u011b nabit\u00fd iont).<\/p>\n

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Miner\u00e1l perovskit krystalizuj\u00edc\u00ed v koso\u010dtvere\u010dn\u00e9 krystalov\u00e9 soustav\u011b.<\/em><\/a><\/p>\n

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Krystalov\u00e1 struktura CaTiO3<\/sub>\u00a0<\/em><\/a><\/p>\n

Dopov\u00e1n\u00edm struktury perovskitu jin\u00fdmi prvky lze doc\u00edlit odli\u0161n\u00fdch fyzik\u00e1ln\u011b-chemick\u00fdch vlastnost\u00ed. To je zp\u016fsobeno \u010d\u00e1ste\u010dnou deformac\u00ed krystalov\u00e9 m\u0159\u00ed\u017eky, ke kter\u00e9 vlivem dopov\u00e1n\u00ed doch\u00e1z\u00ed. Perovskity se tedy uplat\u0148uj\u00ed v\u00a0pom\u011brn\u011b \u0161irok\u00e9m spektru odv\u011btv\u00ed-vyu\u017e\u00edt se kup\u0159\u00edkladu daj\u00ed jejich piezoelektrick\u00e9 vlastnosti (piezokeramick\u00e9 sou\u010d\u00e1stky na b\u00e1zi PbZrO3<\/sub>),\u00a0 katalytick\u00e9 vlastnosti (LaSrMnNiO3<\/sub> se zkoum\u00e1 jako katalyz\u00e1tor redukce oxidu dusn\u00e9ho p\u0159i v\u00fdrob\u011b kyseliny dusi\u010dn\u00e9), zkoumaj\u00ed se i na poli termicky stabiln\u00edch pigment\u016f. Hlavn\u00ed pozornost na sebe ale strh\u00e1vaj\u00ed v\u00a0posledn\u00edch letech tzv. halogenidov\u00e9 perovskity, a to pr\u00e1v\u011b v\u00a0souvislosti s\u00a0fotovoltaick\u00fdmi \u010dl\u00e1nky.<\/p>\n

Obecn\u00fdm vzorcem t\u00e9to skupiny perovskit\u016f je analogicky AMX3<\/sub>, kde A tentokr\u00e1te p\u0159edstavuje nej\u010dast\u011bji methylamoniov\u00fd iont (CH3<\/sub>NH3<\/sub>+<\/sup>), M p\u0159edstavuje kovov\u00fd kation (Pb2+<\/sup>, Sn2+<\/sup>), X n\u00e1le\u017e\u00ed halogenidov\u00e9mu aniontu (Br–<\/sup>, I–<\/sup>). Jedn\u00edm ze z\u00e1stupc\u016f t\u00e9to skupiny l\u00e1tek je methylamonium jodid olovnat\u00fd (CH3<\/sub>NH3<\/sub>PbI3<\/sub>). Ten je intenz\u00edvn\u011b zkoum\u00e1n v\u00a0souvislosti s\u00a0tzv. tandemov\u00fdmi sol\u00e1rn\u00edmi \u010dl\u00e1nky- ty maj\u00ed v\u011bt\u0161\u00ed \u00fa\u010dinnost p\u0159em\u011bny sv\u011btla na elektrickou energii, a to p\u0159i zachov\u00e1n\u00ed relativn\u011b n\u00edzk\u00e9 v\u00fdrobn\u00ed ceny (dle posledn\u00edch v\u00fdzkum\u016f se hranice \u00fa\u010dinnosti pohybuje a\u017e kolem 30 %). V nov\u00fdch tandemov\u00fdch sol\u00e1rn\u00edch \u010dl\u00e1nc\u00edch je na krystalick\u00e9m k\u0159em\u00edku nane\u0161ena vrstva perovskitu. D\u016fvtip tkv\u00ed ve \u201espolupr\u00e1ci\u201c t\u011bchto vrstev. Perovskit toti\u017e absorbuje viditeln\u00e9 fotony o vy\u0161\u0161\u00ed energii, kde\u017eto k\u0159em\u00edk absorbuje fotony o ni\u017e\u0161\u00ed energii (sp\u00ed\u0161e ty z infra\u010derven\u00e9 oblasti elektromagnetick\u00e9ho z\u00e1\u0159en\u00ed). Ukazuje se, \u017ee absorpce \u010d\u00e1st\u00ed spektra slune\u010dn\u00edho z\u00e1\u0159en\u00ed ve v\u00edce vrstv\u00e1ch se zd\u00e1 b\u00fdt \u00fa\u010dinn\u011bj\u0161\u00ed, ne\u017e snaha o vytvo\u0159en\u00ed jedin\u00e9 vrstvy zachycuj\u00edc\u00ed cel\u00e9 spektrum sama (Lal N., N. et al., 2017).<\/p>\n

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Krystalov\u00e1 struktura halogenidov\u00fdch perovskit\u016f<\/em><\/a><\/p>\n

V\u00a0\u010dem dal\u0161\u00edm tkv\u00ed v\u00fdhoda t\u011bchto perovskit\u016f? To, co mimo jin\u00e9 negativn\u011b ovliv\u0148uje \u00fa\u010dinnost fotovoltaick\u00e9ho \u010dl\u00e1nku, jsou defekty v\u00a0krystalov\u00e9 m\u0159\u00ed\u017ece polovodi\u010de. I proto je nutn\u00e9 v\u00a0p\u0159\u00edpad\u011b k\u0159em\u00edkov\u00fdch fotovoltaick\u00fdch \u010dl\u00e1nk\u016f, ale nap\u0159. i t\u011bch z\u00a0germania a dal\u0161\u00edch, p\u0159ipravit t\u00e9m\u011b\u0159 ide\u00e1ln\u00ed monokrystal, co\u017e je ale velice energeticky n\u00e1ro\u010dn\u00e9. Oproti tomu p\u0159\u00edprava perovskit\u016f je pom\u011brn\u011b jednoduch\u00e1. Halogenidov\u00e9 perovskity jsou p\u0159ipravov\u00e1ny za relativn\u011b n\u00edzk\u00fdch teplot (60-90 \u00b0C), co\u017e je v\u00fdhodn\u00e9 pr\u00e1v\u011b s\u00a0ohledem na energetick\u00e9 n\u00e1klady. Jednodu\u0161\u0161\u00ed p\u0159\u00edprava je spojena s\u00a0faktem, \u017ee se u t\u011bchto materi\u00e1l\u016f vyskytuj\u00ed ve v\u011bt\u0161\u00ed m\u00ed\u0159e defekty, jejich\u017e koncentrace je dokonce o n\u011bkolik \u0159\u00e1d\u016f vy\u0161\u0161\u00ed, ne\u017e u monokrystal\u016f. P\u0159esto prozat\u00edm m\u011b\u0159en\u00ed prozrazuj\u00ed, \u017ee defekty v\u00a0tomto p\u0159\u00edpad\u011b ni\u010demu v\u00fdznamn\u011b ne\u0161kod\u00ed. Dal\u0161\u00ed obrovskou v\u00fdhodou je to, \u017ee perovskity sta\u010d\u00ed nan\u00e9st v\u011bt\u0161inou ve vrstv\u011b o velikosti necel\u00e9ho mikrometru, co\u017e p\u0159edstavuje nap\u0159. ve srovn\u00e1n\u00ed s\u00a0k\u0159em\u00edkem v\u00fdrazn\u00e9 \u0161et\u0159en\u00ed materi\u00e1lu. I zde se ale dost\u00e1v\u00e1me k\u00a0p\u00e1r nev\u00fdhod\u00e1m-hlavn\u00ed z\u00a0nich je doposud nevy\u0159e\u0161en\u00e1 ot\u00e1zka stability halogenidov\u00fdch perovskit\u016f. Vzdu\u0161n\u00e1 vlhkost je zkr\u00e1tka nep\u0159\u00edtelem, kv\u016fli n\u011bmu\u017e tyto materi\u00e1ly degraduj\u00ed. Nicm\u00e9n\u011b i zde prob\u00edh\u00e1 intenz\u00edvn\u00ed v\u00fdzkum, kde se studuj\u00ed r\u016fzn\u00e9 polymern\u00ed materi\u00e1ly, kter\u00e9 by degradaci mohly zabr\u00e1nit. Dal\u0161\u00ed nep\u0159\u00edjemnost\u00ed je (p\u0159esto\u017ee minim\u00e1ln\u00ed) obsah problematick\u00fdch prvk\u016f, jako je nap\u0159\u00edklad olovo-hlavn\u011b z legislativn\u00edho hlediska to p\u0159edstavuje probl\u00e9m p\u0159i vy\u0159azov\u00e1n\u00ed takov\u00fdch panel\u016f z\u00a0provozu (recyklaci). I zde se zkoum\u00e1 mo\u017enost vyu\u017eit\u00ed jin\u00fdch, ekologicky m\u00e9n\u011b zat\u011b\u017euj\u00edc\u00edch prvk\u016f (Park, N.G., 2015).<\/p>\n

Osobn\u011b si mysl\u00edm, \u017ee perovskity obecn\u011b p\u0159edstavuj\u00ed skupinu l\u00e1tek, kterou se ur\u010dit\u011b vyplat\u00ed se zab\u00fdvat (j\u00e1 jsem se jim v\u011bnovala na vysok\u00e9 \u0161kole). Jejich rozmanit\u00e9 fyzik\u00e1ln\u011b-chemick\u00e9 vlastnosti maj\u00ed velk\u00fd potenci\u00e1l pozitivn\u011b se projevovat v\u00a0mnoh\u00fdch odv\u011btv\u00edch v\u011bdy a pr\u016fmyslu.<\/p>\n

 <\/p>\n

Zdroje:<\/strong><\/p>\n

Park, N. G. (2015). Perovskite solar cells: an emerging photovoltaic technology. Materials today, 18(2), 65-72.<\/p>\n","protected":false},"excerpt":{"rendered":"

V\u00a0minul\u00e9 \u010d\u00e1sti jsme si nast\u00ednili, co to vlastn\u011b fotovoltaika je a jak funguj\u00ed fotovoltaick\u00e9 \u010dl\u00e1nky. Narazili jsme u toho na jeden fyzik\u00e1ln\u00ed limit, a to teoretickou hranici \u00fa\u010dinnosti p\u0159em\u011bny slune\u010dn\u00ed energie na energii elektrickou, kter\u00e1 se nap\u0159\u00edklad pro k\u0159em\u00edkov\u00e9 \u010dl\u00e1nky pohybuje m\u00edrn\u011b nad 30 %. Co si budeme nalh\u00e1vat, vzhledem k\u00a0tomu, \u017ee v\u00a0praxi se dosahuje […]<\/p>\n","protected":false},"author":20,"featured_media":5378,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false},"version":2}},"categories":[6],"tags":[],"coauthors":[271],"class_list":["post-5388","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-other","entry","has-media"],"jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/www.enviblog.cz\/blog\/wp-content\/uploads\/2022\/04\/20210911_105605.jpg","jetpack_shortlink":"https:\/\/wp.me\/pa1A1I-1oU","_links":{"self":[{"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/posts\/5388","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/users\/20"}],"replies":[{"embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/comments?post=5388"}],"version-history":[{"count":1,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/posts\/5388\/revisions"}],"predecessor-version":[{"id":5392,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/posts\/5388\/revisions\/5392"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/media\/5378"}],"wp:attachment":[{"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/media?parent=5388"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/categories?post=5388"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/tags?post=5388"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/coauthors?post=5388"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}