{"id":5373,"date":"2022-04-06T06:45:48","date_gmt":"2022-04-06T04:45:48","guid":{"rendered":"https:\/\/www.enviblog.cz\/blog\/?p=5373"},"modified":"2022-04-06T08:54:30","modified_gmt":"2022-04-06T06:54:30","slug":"perovskity-nadeje-pro-fotovolatiku-i-dil","status":"publish","type":"post","link":"https:\/\/www.enviblog.cz\/blog\/2022\/04\/06\/perovskity-nadeje-pro-fotovolatiku-i-dil\/","title":{"rendered":"Perovskity-nad\u011bje pro fotovoltaiku? – I. d\u00edl"},"content":{"rendered":"

V\u00a0posledn\u00edch letech obecn\u011b roste z\u00e1jem o tzv. \u201ezelenou elekt\u0159inu\u201c, tedy elekt\u0159inu vyrobenou v\u00fdhradn\u011b z\u00a0obnoviteln\u00fdch zdroj\u016f. \u0158e\u010d je o v\u011btrn\u00fdch, vodn\u00edch \u010di slune\u010dn\u00edch elektr\u00e1rn\u00e1ch,\u00a0 ale tak\u00e9 se vyu\u017e\u00edv\u00e1 geoterm\u00e1ln\u00ed energie \u010di energie z biomasy. Ka\u017ed\u00e1 z\u00a0uveden\u00fdch alternativ m\u00e1 sv\u00e1 pro a proti, p\u0159i\u010dem\u017e velk\u00e9 diskuze prob\u00edhaj\u00ed pr\u00e1v\u011b kolem fotovoltaiky. Poj\u010fme si o tomto t\u00e9matu pov\u011bd\u011bt v\u00edce.<\/strong><\/em><\/p>\n

Nejprve trocha nutn\u00e9 teorie. Fotovoltaika, tedy odv\u011btv\u00ed vyu\u017e\u00edvaj\u00edc\u00ed \u00a0p\u0159em\u011bny energie slune\u010dn\u00edho z\u00e1\u0159en\u00ed na energii elektrickou (stejnosm\u011brn\u00fd elektrick\u00fd proud), je v\u00a0posledn\u00ed dob\u011b jedno z\u00a0nejrychleji rostouc\u00edch odv\u011btv\u00ed v\u00fdroby obnoviteln\u00e9 energie v\u016fbec. Z\u00e1kladn\u00ed princip je zalo\u017een na fotovoltaick\u00e9m jevu-zcela zjednodu\u0161en\u011b se jedn\u00e1 o interakci mezi fotony (kvanta energie elektromagnetick\u00e9ho vln\u011bn\u00ed) a polovodi\u010dov\u00fdm materi\u00e1lem. Polovodi\u010d je l\u00e1tka, kter\u00e1 se za ur\u010dit\u00fdch okolnost\u00ed chov\u00e1 jako izolant a nevede elektrick\u00fd proud, za jin\u00fdch podm\u00ednek se ale st\u00e1v\u00e1 vodi\u010dem. Jist\u011b zn\u00e1te v\u00a0souvislosti s\u00a0polovodi\u010di k\u0159em\u00edk, kter\u00fd se stal synonymem pro \u010dipy. S\u00a0t\u011bmi se setk\u00e1v\u00e1me u po\u010d\u00edta\u010d\u016f, ale i mobiln\u00edch telefon\u016f nebo t\u0159eba u dom\u00e1c\u00edch spot\u0159ebi\u010d\u016f. Vodivost polovodi\u010d\u016f m\u016f\u017ee b\u00fdt vlastn\u00ed (kdy se v\u00a0nich nenach\u00e1z\u00ed \u017e\u00e1dn\u00e9 p\u0159\u00edm\u011bsi), ale i p\u0159\u00edm\u011bsov\u00e1, kdy se do z\u00e1kladn\u00ed m\u0159\u00ed\u017eky polovodi\u010de vkl\u00e1daj\u00ed atomy jin\u00fdch prvk\u016f (pak rozli\u0161ujeme polovodi\u010de typu N, kde jsou majoritn\u00edmi nositeli n\u00e1boje elektrony, a polovodi\u010de typu P, kde majoritn\u00edmi nositeli n\u00e1boje jsou kladn\u011b nabit\u00e9 d\u00edry).<\/p>\n

Fotovoltaick\u00fd \u010dl\u00e1nek je ve sv\u00e9 podstat\u011b velkoplo\u0161n\u00e1 polovodi\u010dov\u00e1 dioda s\u00a0PN p\u0159echodem (spojen\u00ed polovodi\u010de typu N a polovodi\u010de typu P). Typickou vlastnost\u00ed tohoto p\u0159echodu je jeho usm\u011br\u0148ovac\u00ed \u00fa\u010dinek, kdy v jednom sm\u011bru j\u00edm elektrick\u00fd proud proch\u00e1zet m\u016f\u017ee, kde\u017eto ve sm\u011bru opa\u010dn\u00e9m nikoli. V\u00a0principu jde tedy o to, \u017ee foton, kter\u00fd m\u00e1 dostate\u010dnou energii, m\u016f\u017ee v polovodi\u010dov\u00e9m materi\u00e1lu zp\u016fsobit uvoln\u011bn\u00ed elektronu z\u00a0jeho krystalov\u00e9 m\u0159\u00ed\u017eky. PN p\u0159echod ov\u0161em zp\u016fsob\u00ed, \u017ee elektron uvoln\u011bn\u00fd z\u00a0vrstvy N se nem\u016f\u017ee rekombinovat s\u00a0kladn\u011b nabit\u00fdmi d\u011brami vyskytuj\u00edc\u00edmi se ve vrstv\u011b P a hromad\u00ed se tedy ve vrstv\u011b N, ov\u0161em elektrony z\u00a0vrstvy P do vrstvy N proch\u00e1zet mohou. Na p\u0159echodu PN se tedy v\u00a0kone\u010dn\u00e9m d\u016fsledku vytvo\u0159\u00ed elektrick\u00e9 nap\u011bt\u00ed (u k\u0159em\u00edkov\u00fdch \u010dl\u00e1nk\u016f dosahuje cca 0,5 V). Je-li k \u010dl\u00e1nku p\u0159ipojen spot\u0159ebi\u010d,\u00a0 obvodem za\u010dne prot\u00e9kat elektrick\u00fd proud. V\u00a0praxi se za \u00fa\u010delem zv\u00fd\u0161en\u00ed v\u00fdstupn\u00edho nap\u011bt\u00ed jednotliv\u00e9 fotovoltaick\u00e9 \u010dl\u00e1nky zapojuj\u00ed do v\u011bt\u0161\u00edch celk\u016f, tzv. sol\u00e1rn\u00edch panel\u016f (Lincot D., 2017).<\/p>\n

\"\"<\/a>
Zjednodu\u0161en\u00e9 sch\u00e9ma struktury fotovoltaick\u00e9ho k\u0159em\u00edkov\u00e9ho \u010dl\u00e1nku (https:\/\/oze.tzb-info.cz\/fotovoltaika\/11772-nejpouzivanejsi-pojmy-ve-fotovoltaice)<\/em><\/figcaption><\/figure>\n

 <\/p>\n

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Ralsko-nejv\u011bt\u0161\u00ed fotovoltaick\u00e1 elektr\u00e1rna v \u010cR (http:\/\/www.fotovoltaickepanely.eu\/fotovoltaika\/nejvetsi-ceske-elektrarny\/)<\/em><\/figcaption><\/figure>\n

Existuje n\u011bkolik druh\u016f fotovoltaick\u00fdch panel\u016f. Mezi ty nejz\u00e1kladn\u011bj\u0161\u00ed pat\u0159\u00ed monokrystalick\u00e9 k\u0159em\u00edkov\u00e9 panely, polykrystalick\u00e9 a amorfn\u00ed. P\u0159ednost\u00ed monokrystalick\u00fdch panel\u016f je jejich \u00fa\u010dinnost v\u00a0rozmez\u00ed 17-22 %, nev\u00fdhodou je jejich vy\u0161\u0161\u00ed cena a po\u017eadavky na spr\u00e1vnou orientaci panel\u016f v\u016f\u010di slunci (orientace na jih, optim\u00e1ln\u00ed n\u00e1klon panel\u016f). Proces v\u00fdroby monokrystalick\u00e9ho k\u0159em\u00edku je technologicky velice n\u00e1ro\u010dn\u00fd a n\u00e1kladn\u00fd. K\u0159em\u00edkov\u00fd monokrystal se p\u0159ipravuje tzv. Czochralskeho metodou ta\u017een\u00edm z\u00a0taveniny k\u0159em\u00edku p\u0159i teplot\u00e1ch kolem 1400 \u00b0C v\u00a0ochrann\u00e9 atmosf\u00e9\u0159e (Yu, X. et al., 2013). \u00a0U polykrystalick\u00fdch panel\u016f se uv\u00e1d\u00ed\u00a0 \u00fa\u010dinnost 14-16 % (je zde tedy v\u011bt\u0161\u00ed po\u017eadavek na prostor), jsou ov\u0161em m\u00e9n\u011b n\u00e1ro\u010dn\u00e9 na v\u00fdrobu a o n\u011bco l\u00e9pe pracuj\u00ed s\u00a0rozpt\u00fdlen\u00fdm sv\u011btlem (zata\u017een\u00e1 obloha, mlha..). St\u00e1le ov\u0161em plat\u00ed, \u017ee u t\u011bchto dvou zm\u00edn\u011bn\u00fdch typ\u016f se jak\u00fdkoli st\u00edn \u010di z\u00e1stavba projev\u00ed v\u00edce \u010di m\u00e9n\u011b negativn\u011b na jejich v\u00fdkonu. Cenov\u011b nejp\u0159\u00edzniv\u011bj\u0161\u00ed, ale s\u00a0nejni\u017e\u0161\u00ed \u00fa\u010dinnost\u00ed (max. 11 %), jsou amorfn\u00ed panely (tenk\u00e9 vrstvy k\u0159em\u00edku nane\u0161en\u00e9 na nap\u0159. sklen\u011bn\u00e9m podkladu). Jejich p\u0159ednost\u00ed je jejich n\u00edzk\u00e1 hmotnost a fakt, \u017ee obstojn\u011b pracuj\u00ed s\u00a0rozpt\u00fdlen\u00fdm sv\u011btlem a dok\u00e1\u017e\u00ed tak l\u00e9pe pracovat i p\u0159i obla\u010dnosti \u010di ne zcela ide\u00e1ln\u00ed orientaci panel\u016f v\u016f\u010di slunci.<\/p>\n

Z\u00e1kladem fotovoltaick\u00fdch sol\u00e1rn\u00edch \u010dl\u00e1nk\u016f nemus\u00ed b\u00fdt nutn\u011b k\u0159em\u00edk, ale nap\u0159\u00edklad arsenid galia, tellurid kadmia aj. Ka\u017ed\u00fd panel je p\u0159itom obalen n\u011bkolika ochrann\u00fdmi vrstvami\u00a0\u2013z jedn\u00e9 strany to b\u00fdv\u00e1 nej\u010dast\u011bji sklo, z druh\u00e9 plast. D\u00e1le to je lamina\u010dn\u00ed f\u00f3lie, nej\u010dast\u011bji z\u00a0EVA (ethylen-vinyl-acet\u00e1t), mezi kter\u00e9 jsou vlo\u017eeny vodiv\u011b spojen\u00e9 fotovoltaick\u00e9 \u010dl\u00e1nky, a nesm\u00ed chyb\u011bt ani r\u00e1m (nej\u010dast\u011bji hlin\u00edkov\u00fd), kter\u00fd zvy\u0161uje odolnost panelu v\u016f\u010di mechanick\u00e9mu nam\u00e1h\u00e1n\u00ed.<\/p>\n

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K\u0159em\u00edkov\u00fd ingot (monokrystalick\u00fd k\u0159em\u00edk) vyroben\u00fd Czochralsk\u00e9ho metodou. (https:\/\/diit.cz\/clanek\/cena-kremiku-stoupla-na-ctyrnasobek)<\/em><\/figcaption><\/figure>\n

Z hlediska ochrany \u017eivotn\u00edho prost\u0159ed\u00ed se jedn\u00e1 v\u00a0p\u0159\u00edpad\u011b fotovoltaick\u00fdch elektr\u00e1ren o velice \u010dist\u00fd zp\u016fsob v\u00fdroby elektrick\u00e9 energie, jeliko\u017e je bezemisn\u00ed (emise vznikaj\u00ed p\u0159ev\u00e1\u017en\u011b p\u0159i v\u00fdrob\u011b panel\u016f) a nehlu\u010dn\u00fd, p\u0159i\u010dem\u017e prim\u00e1rn\u00ed zdroj energie je prakticky nevy\u010derpateln\u00fd (ne\u017e se Slunce stane b\u00edl\u00fdm trpasl\u00edkem, bude n\u00e1m je\u0161t\u011b p\u00e1r miliard let slou\u017eit). M\u00e1 to ov\u0161em i sv\u00e9 nev\u00fdhody. Z hlediska vyu\u017e\u00edv\u00e1n\u00ed sol\u00e1rn\u00ed energie je nejd\u016fle\u017eit\u011bj\u0161\u00edm faktorem intenzita slune\u010dn\u00edho z\u00e1\u0159en\u00ed a tak\u00e9 po\u010det hodin slune\u010dn\u00edho svitu v jednotliv\u00fdch ro\u010dn\u00edch obdob\u00edch. Dostupnost sol\u00e1rn\u00ed energie je tedy siln\u011b z\u00e1visl\u00e1 na po\u010das\u00ed a ro\u010dn\u00edm obdob\u00ed. To jsou faktory, kter\u00e9 se v\u00a0na\u0161ich zem\u011bpisn\u00fdch \u0161\u00ed\u0159k\u00e1ch mus\u00ed v\u017edy zv\u00e1\u017eit. Dal\u0161\u00ed nev\u00fdhodou fotovoltaick\u00fdch panel\u016f je jejich \u017eivotnost, jeliko\u017e panely postupn\u011b degraduj\u00ed a ztr\u00e1cej\u00ed svou \u00fa\u010dinnost. V\u00a0dne\u0161n\u00ed dob\u011b poskytuj\u00ed v\u00fdrobci garanci minim\u00e1ln\u011b 25 let v\u00fdkonu na\u00a080 %\u00a0jmenovit\u00e9ho v\u00fdkonu, i kdy\u017e celkov\u00e1 \u017eivotnost panelu b\u00fdv\u00e1 i o\u00a010 let del\u0161\u00ed.<\/p>\n

Jen\u017ee jako asi ka\u017ed\u00fd fyzik\u00e1ln\u00ed jev, m\u00e1 i ten fotovolatick\u00fd sv\u016fj limit. Jedn\u00e1 se o tzv. Shockley\u016fv\u2013Queisser\u016fv limit teoretick\u00e9 maxim\u00e1ln\u00ed \u00fa\u010dinnosti p\u0159em\u011bny slune\u010dn\u00edho z\u00e1\u0159en\u00ed na elekt\u0159inu pro fotovoltaick\u00fd \u010dl\u00e1nek s jedn\u00edm PN p\u0159echodem, p\u0159i\u010dem\u017e hodnota tohoto limitu z\u00e1vis\u00ed v\u017edy na konkr\u00e9tn\u00edm druhu pou\u017eit\u00e9ho polovodi\u010dov\u00e9ho materi\u00e1lu (\u0161\u00ed\u0159ce zak\u00e1zan\u00e9ho p\u00e1su) a spektr\u00e1ln\u00edm slo\u017een\u00ed z\u00e1\u0159en\u00ed. Nap\u0159\u00edklad pro krystalick\u00fd k\u0159em\u00edk se \u0161\u00ed\u0159kou zak\u00e1zan\u00e9ho p\u00e1su 1,1 eV je Shockley\u016fv\u2013Queisser\u016fv limit m\u00edrn\u011b nad 30 % (R\u00fchle, S. 2016). V\u00a0praxi dosahuj\u00ed k\u0159em\u00edkov\u00e9 sol\u00e1rn\u00ed \u010dl\u00e1nky \u00fa\u010dinnosti p\u0159em\u011bny je\u0161t\u011b ni\u017e\u0161\u00ed, a to hlavn\u011b kv\u016fli energetick\u00fdm ztr\u00e1t\u00e1m (ne v\u0161echny fotony dopadaj\u00edc\u00ed na \u010dl\u00e1nek se p\u0159em\u011bn\u00ed na elektrickou energii, \u010d\u00e1st se vyz\u00e1\u0159\u00ed nap\u0159. ve form\u011b tepla).<\/p>\n

Lze teoreticky tuto hranici \u00fa\u010dinnosti u fotovoltaick\u00fdch \u010dl\u00e1nk\u016f p\u0159ekonat? A jak\u00fdm zp\u016fsobem? O tom ve druh\u00e9 \u010d\u00e1sti \u010dl\u00e1nku.<\/p>\n

 <\/p>\n

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

Lincot, D. (2017). The new paradigm of photovoltaics: From powering satellites to powering humanity.\u00a0Comptes Rendus Physique,\u00a018(7-8), 381-390.<\/p>\n

Yu, X., Chen, J., Ma, X., & Yang, D. (2013). Impurity engineering of Czochralski silicon. Materials Science and Engineering: R: Reports, 74(1-2), 1-33.<\/p>\n

R\u00fchle, S. (2016). Tabulated values of the Shockley\u2013Queisser limit for single junction solar cells. Solar energy, 130, 139-147.<\/p>\n","protected":false},"excerpt":{"rendered":"

V\u00a0posledn\u00edch letech obecn\u011b roste z\u00e1jem o tzv. \u201ezelenou elekt\u0159inu\u201c, tedy elekt\u0159inu vyrobenou v\u00fdhradn\u011b z\u00a0obnoviteln\u00fdch zdroj\u016f. \u0158e\u010d je o v\u011btrn\u00fdch, vodn\u00edch \u010di slune\u010dn\u00edch elektr\u00e1rn\u00e1ch,\u00a0 ale tak\u00e9 se vyu\u017e\u00edv\u00e1 geoterm\u00e1ln\u00ed energie \u010di energie z biomasy. Ka\u017ed\u00e1 z\u00a0uveden\u00fdch alternativ m\u00e1 sv\u00e1 pro a proti, p\u0159i\u010dem\u017e velk\u00e9 diskuze prob\u00edhaj\u00ed pr\u00e1v\u011b kolem fotovoltaiky. Poj\u010fme si o tomto t\u00e9matu pov\u011bd\u011bt v\u00edce. […]<\/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":[273],"coauthors":[271],"class_list":["post-5373","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-other","tag-perovskity","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-1oF","_links":{"self":[{"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/posts\/5373","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=5373"}],"version-history":[{"count":3,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/posts\/5373\/revisions"}],"predecessor-version":[{"id":5380,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/posts\/5373\/revisions\/5380"}],"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=5373"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/categories?post=5373"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/tags?post=5373"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.enviblog.cz\/blog\/wp-json\/wp\/v2\/coauthors?post=5373"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}