Yaya Za a Yanke Kwayoyin Rana Masu Yawa Da Kyau?
Teburin Abubuwan Ciki
Amsa mai sauri: Yanke cikakken tantanin halitta zuwa rabi, kashi uku ko ƙananan guda yana ƙara ƙarfin module ta hanyar rage yawan wutar da kowane ɗan tsiri ke ɗauka, wanda ke rage asarar juriya a cikin ribbon. Amfanin yana raguwa yayin da tsiri ke ƙarami, kuma farashin inji yana ƙaruwa. Hanyoyi uku ne suka fi rinjaye. Rubutun Laser da ke biye da karyewar inji shine mafi sauri kuma yana gabatar da mafi ƙarancin nauyin zafi, amma ingancin gefen karyewar ya dogara da zurfin rubutun. Cikakken yankan Laser yana raba tantanin halitta da katako shi kaɗai kuma yana ba da gefe mai tsafta a ƙananan gudu. Rarraba Laser na zafi yana haɗa Laser da matakin sanyaya don fashewar ta yaɗa ta hanyar da aka sarrafa. Girman da ya dace ya tashi daga tsawon igiyar Laser na 532 nm ta girman fasali kusa da 1 µm da 20 µm zuwa 100 µm, kuma wutar lantarki ta tsiri tana da ƙasa — kusan 0.55 V — don haka ribar tana zuwa daga juriya, ba daga wutar lantarki ba.
PV Module Manufacturing · na Jerry, Ooitech
Gabatarwa
TOPCon, SHJ da BC Kwayoyin" title="Yaya za a Yanke Kwayoyin Solar Masu Sassa da Yawa Mafi Kyau? Gaskiyar da Ta Saba da Hankali Game da Asarar Gefen a cikin n-type TOPCon, SHJ da BC Kwayoyin"/>
Don neman ƙarin ƙarfin module, injiniyoyi sukan yanka babban ƙwayar guda ɗaya zuwa 1/2, 1/3 ko ma fiye da "ƙananan ƙwayoyi", sannan su sake haɗa su a jeri da layi daya a cikin module. Manufar ita ce rage yawan wutar lantarki da rage asarar ƙarfin juriya. Amma kowane yanka yana barin "rauni" marar kariya a gefen ƙwayar. Waɗannan raunuka sun zama tarko na masu ɗaukar kaya, kuma suna rage ƙarfin buɗe kewayawa (Voc) da ma'aunin cika (FF). Ƙaramin ƙwayar ya zama, wannan asarar sake haɗuwa a gefen tana ƙara cutarwa.
Hanyar masana'antu da aka fi amfani da ita a yau, "laser scribing + mechanical cleaving" (L&C), tana barin mummunar lalacewar zafi tare da yanke. Kuma shekaru da yawa filin ya yarda da abu ɗaya: yin rubutu a gefen p-n junction yana yin lalacewa mafi girma, don haka "gefen p-n junction shine babban matsalar asarar gefe". Wannan imani ya haifar da dabarar da aka saba da ita ta "yin rubutu daga gefen n-n+ don kare p-n junction".
Amma shin wannan "hankali na kowa" da aka yarda da shi da gaske yana nuna ainihin halayen lantarki na p-n junction? Ko kuma kawai alamar zafin laser ne?
Babban Sakamako: Halayen Lantarki na Ciki Wanda Ya Keta Yarjejeniya
Ƙungiyar bincike a cibiyar FUNSOM ta Jami'ar Soochow ta buga aiki a cikin Nano Energy ta amfani da sabuwar hanyar yanke mai ƙarancin lalacewa da suke kira "45° rotational cleaving". Tana guje wa lalacewar zafin laser cikin wayo kuma tana bincika ainihin halayen lantarki na gefen p-n junction. Sakamakon ya ba masana'antar mamaki:
Ƙarƙashin yanke mai ƙarancin lalacewa, ƙarfin tattara masu ɗaukar wutar lantarki a gefen p-n junction ya fi na gefen n-n+ girma. A cikin kalmomi masu sauƙi: yin rubutu daga gefen p-n junction shine mafi kyawun dabarar masana'antu. Wannan ya juya shekaru ashirin na aikin da aka yarda da shi.
Yadda ake Bude Gefen Cell Ba tare da Cutar da shi ba
Don yin nazarin "halayen lantarki na asali na haɗin p-n", da farko dole ne ka warware wata matsala mai wahala. Na gargajiya yankan laser yana barin wani Layer da aka sake narkewa kuma aka sake ƙarfafa, tare da ƙananan fashe-fashe da tarin lalacewar zafi a gefen, kuma duk wannan yana ɓata duk wani lura na haɗin p-n da halayen sake haɗuwa na saman. Ƙungiyar ta bi wata hanya ta daban, ta yin amfani da yanayin tsagewar anisotropic na lu'ulu'u na silicon don ba da shawarar hanyar "tsagewar juyawa 45°":
Mataki na ɗaya: juya wafer 45° a cikin jirgin.
Mataki na biyu: fara zana layi marar zurfi a kan (100) jirgin da diamond scriber.
Mataki na uku: tsaga tare da {110} jirgin iyali don samun sashe mai faɗi atomically, ba tare da lalacewar zafi ba.
Gefen sashe da aka samu ta wannan hanyar yana kiyaye mutuncin tsari da lantarki. Haɗe da fasahar hoton photovoltage na micrometer-resolution, za ka iya duba halayyar lantarki kusa da gefen wuri zuwa wuri, ba tare da cutar da p-n junction ba.
Gwajin ya yi amfani da laser na 532 nm (zurfin shiga kusan 1.3 µm), wanda ya kai kusan 1 µm girman sarari a ƙarƙashin maƙasudin 50×, bayyananne don ɗaukar halin raguwar ƙarfin lantarki a cikin dubun micrometers na gefen.
Sakamakon Gwaji
Hoto 1. Tasirin yanke akan ingancin p-n junction (a, b), zanen hanyar 45° juyawa don tsaga (c, d), da zanen tsarin sel masu inganci guda uku (e-g).
Hoto 1a yana nuna tsarin L&C na gargajiya da aka rubuta a gefen p-n junction: da farko laser yana ƙone wani rami a saman sel (alamar Laser), sannan ƙarfin injiniya ya raba sel. Hoto 1b shine SEM cross-section na gefen bayan yanke L&C. Kuna iya ganin a fili cewa sashin ya rabu zuwa yankuna biyu. Babban ɓangaren shine "yankin ablation na laser", yana nuna bayyanannen yanayin sake narkewa da sake ƙarfafawa. Ƙananan ɓangaren shine "yankin da aka raba da damuwa", wanda aka tsaga da ƙarfin injiniya, yana barin ƙananan ƙwayoyin cuta da yawa marasa tsari da wuraren narkewa. Wannan lalacewar zafi shine ainihin abin da ke haifar da haɓakar leakage current da raguwar aikin sel.
Ya kamata a lura: lokacin da laser ya rubuta a gefen p-n junction, p-n junction ɗin kanta tana lalacewa gaba ɗaya ta hanyar zafi. Don haka "al'amarin" da masana'antu ke gani koyaushe, cewa "gefen p-n junction shine mafi yawan asarar gefe", a gaskiya sakamakon lalacewar zafi ne.
Hoto 1c yana nuna hanyar yanke juyawa 45° da aka gabatar a nan: juya wafer 45° a kusa da axis na cikin jirgin, rubuta (100) plane da diamond scriber, sannan tsaga tare da {110} cleaving plane. Hoto 1d shine hoton SEM na gefen da aka yanke, ma'aunin sikelin 20 µm. Yankin giciye yana da matuƙar lebur da tsabta, babu alamun narkewa kwata-kwata, yana kiyaye tsari da ingancin lantarki na p-n junction sosai. Wannan shine mabuɗin nazarin "halin ciki".
Wannan aikin yana duban manyan fasahohin sel masu inganci na n-type guda uku: TOPCon, SHJ da TBC. Suna da alaƙa guda ɗaya. A kan n-type c-Si substrate suna ɗaukar duka p-n junction (homo- ko heterojunction) da n-n+ high-low junction. Don haka nazarin halayen gefensu yana ba da jagora kai tsaye ga samarwa na masana'antu na gaske.
Hoto 2. Nazarin photovoltage na gefen gaba na sel TOPCon, SHJ da TBC.
Hoto na 2a yana nuna duban laser na 532 nm daga gefen gaban tantanin halitta zuwa ciki, yana aiki tare da matakin daidaiton XY da amplifier na lantarki don yin rikodin siginar photovoltage a lokaci guda, a ƙarshe yana gina taswirar photovoltage mai girma biyu. Hoto na 2b shine hoton photovoltage na gaba na TOPCon, SHJ da TBC (daga hagu zuwa dama). Launi mai haske yana nufin mafi girman photovoltage. Dukkanin sel guda uku suna nuna "band mai gradient" a fili a cikin ~100 µm na gefen, ƙananan photovoltage kusa da gefen. Wannan shine shaida kai tsaye na asarar sake haɗuwa a gefen.
Idan aka kwatanta ukun: TOPCon yana da mafi girman photovoltage (0.40–0.55 V) kuma yana cika da sauri. TBC yana da mafi ƙanƙanta (0.36–0.49 V) kuma yana raguwa a hankali, ma'ana sake haɗuwar gefensa ita ce mafi muni. Wannan sakamakon ya saba wa sanin gama gari na "p-n junction shine mabuɗin", saboda gefen gaba (gefen da ke fuskantar haske) yawanci shine inda p-n junction take.
Hoto na 2c yana daidaita bayanin photovoltage da aka fitar tare da layin da aka yanke a cikin Hoto na 2b. Dukkanin lanƙwasa guda uku suna nuna "ƙananan a gefen, babba a kan tudu", amma saurin cikawa (wanda ke nuna tsawon sake haɗuwa a gefen) ya bambanta a fili:
TOPCon: mafi gajeren yanki na raguwa, kusan cikawa a cikin ~100 µm, mafi ƙarancin asarar gefen.
SHJ: matsakaicin yanki na raguwa, kusan cikawa a ~200 µm.
TBC: mafi jinkirin farfadowa, yana miƙe har zuwa ~500 µm kafin cikakken jikewa, mafi munin asarar gefe.
Hoto 2d yana bayyana kimiyyar da ke bayan bambance-bambancen. Ɗan rami da aka samar ta hanyar haske yana ƙarewa yana yin ɗaya daga cikin abubuwa biyu: ana tattara shi ta hanyar lantarki, ko kuma ya karkata zuwa gefe ya sake haɗuwa.
TOPCon: emitter a gaba, hanya gajeriyar tattara ramuka
Fuskar gaba ita ce p+ emitter. Ramuka kawai suna buƙatar ƙetare emitter mai sirara sosai don a tattara su ta hanyar lantarki na gaba, don haka yawancin ramuka "ba su samun damar" isa gefe. A lokaci guda, ƙarfin filin da p+ emitter / SiOx / n-poly-Si ke samarwa yana nan aiki a gefe kuma, yana raba masu ɗaukar kaya da sauri. Wannan shine tushen dalilin da yasa TOPCon ke da mafi ƙarancin asarar gefe.
SHJ: gaba yana tattara electrons, ramuka suna ɗaukar hanya mai tsawo
Fuskar gaba ta SHJ ita ce n-a-Si:H, wadda ke tattara electrons. Ramuka dole su bazu har zuwa baya p-a-Si:H kafin a tattara su, hanya mai tsawo sosai. Ƙara da TCO mai ɗaukar nauyi mai yawa wanda ke aiki kamar "babbar hanya", tana ɗaukar ramuka da yawa a gefe, kuma sake haɗuwa a gefe yana ƙaruwa sosai.
TBC: duk lantarki a baya, lalacewa gaba ɗaya
A cikin TBC kowace na'urar lantarki tana zaune a baya. Masu ɗaukar kaya da aka samar a saman gaba dole ne su yi tafiya a kwance a duk faɗin wafer don a tattara su. Mafi muni, shafin Al2O3 na gaba yana ɗauke da caji mara kyau mai yawa, yana haifar da rukunin ramuka a saman Si kuma yana samar da "hanyar gudanar da ramuka" wanda ke tura ramuka da ƙarfi zuwa gefen.
Bayanan kula da sauri: halin photovoltage na gaba yana dogara ne akan abubuwa biyu, "nisa tattara masu ɗaukar kaya" da "ko akwai hanyar jigilar kaya a kwance", kuma ba shi da alaƙa da alkiblar haɗin p-n da kansa.
Hoto 3. Binciken photovoltage na gefen baya na TOPCon, SHJ da sel TBC.
Hoto na 3a yana zana leza na dubawa daga gefen baya. Hoto na 3b shine taswirar photovoltage mai girma biyu da ta dace. Idan aka kwatanta da Hoto na 2b, dukkan sel guda uku suna nuna ƙarancin photovoltage na baya fiye da na gaba (saboda fuskar gaba yawanci tana da ingantaccen tsarin hana haske da kuma amfani da haske mai girma). Hoto na 3c yana bayyana wani abu mai ban sha'awa: "mai nasara" na gefen baya ya zama TBC. Ko da yake SHJ ma yana da p-n junction a baya, photovoltage na gefensa a zahiri ya fi TOPCon ƙasa, wanda hakan ya ƙara nuna cewa "matsayin p-n junction" ba shine kawai abin da ke tantance asarar gefe ba. Hoto na 3d yana zana tsarin jigilar masu ɗaukar ƙarancin ƙarfi na gefen baya. Baya na musamman: n-poly-Si na baya yana riƙe da babban taro na electrons, yana samar da yanayi mai ƙarfi wanda ke danne holes amma yana inganta tattara electrons.
Gefen baya na TOPCon: "hanyar sauri" na hole an danne shi
Babban taro na electrons a cikin n-poly-Si na baya yana danne jigilar holes. Holes dole ne su ratsa dukkan n-type c-Si substrate don su isa ga p+ emitter na gaba kafin a tattara su. Wannan "jigilar nesa mai nisa" yana sa photovoltage na gefen baya ya zama ƙasa gabaɗaya, amma kuma yana rage yawan holes da ke isa gefe.
Gefen baya na SHJ: heterojunction yana da ƙarfi, amma TCO takobi ne mai kaifi biyu
SHJ's n-type c-Si / p-a-Si:H heterojunction really does offer stronger carrier separation than TOPCon, but its TCO has low lateral resistance and still "short-circuits" a fair share of holes to the edge. The result: strong separation ability does not equal small edge loss.
TBC back side: the hole HSC is right there on the back, a home-court advantage
TBC's back-side HSC faces the photogenerated holes directly. Carriers get collected right on the back, so far fewer flow to the edge, and the back-side photovoltage saturates fastest.
Quick note: back-side photovoltage behavior shows a "reversed" trend versus the front. TBC is worst on the front but best on the back, showing that "which side faces the light" matters more than "which side is the p-n junction".
Figure 4. Cross-sectional photovoltage distribution model of TOPCon and SHJ cells.
Idan Figures 2 da 3 sun kalli gefen "daga gefe", to Figure 4 ya yanka shi "a tsaye". Laser din yana dubawa kai tsaye a kan yankin da aka yanka, don haka kana ganin dukkan halayen lantarki daga p-n junction zuwa n-n+ a cikin harbi daya. Wannan shi ne mafi asali bangare na binciken. Figure 4a ita ce taswirar photovoltage na yankin da aka yanka na TOPCon, daga hagu zuwa dama gefen gaba (p+ emitter / p-n junction) da gefen baya (n-poly-Si / n-n+ junction). Kana iya ganin gefen hagu (p-n junction) ya fi haske gaba daya, kuma gefen dama (n-n+) ya fi duhu. Lankwasawa da aka fitar a Figure 4b a bayyane take: daga gefen p-n junction zuwa gefen n-n+, photovoltage yana raguwa a tsari, tare da dukkan yankin da ke raguwa kusan 100 µm. Wannan sakamako ya ƙi karɓar ra'ayin gargajiya cewa "p-n junction ita ce matsalar asarar gefe", domin a ƙarƙashin yanayin ƙarancin lalacewa gefen p-n junction a maimakon haka shi ne yankin mai yawan photovoltage. Figure 4c yana ba da dalilin zahiri: a gefen p-n junction (p+ emitter) ƙananan masu ɗaukar kaya (holes) suna tafiya ɗan gajeren nisa kawai don a tattara su, yayin da a gefen n-n+ (yankin n-poly-Si) holes dole su tsallaka dukkan n-type c-Si don su isa p+ emitter, hanya mai tsawo mai yawan yiwuwar sake haɗuwa, don haka asarar ta fi girma. Figures 4d–f sun nuna daidai wannan yanayin akan sel SHJ: daga p-n junction na baya (p-a-Si:H / n-c-Si) zuwa n-n+ junction na gaba (i/n-a-Si:H / n-c-Si), photovoltage kuma yana raguwa a tsari. Wannan ka'ida da ke aiki a kan tsarin sel daban-daban ita ce ɗaya daga cikin muhimman hujjojin binciken.
Don a bayyana wannan daidai, ƙungiyar ta samo samfurin watsa ƙananan masu ɗaukar nauyi mai girma ɗaya. Hoto 4g shine tsarin samfurin, yana nuna lanƙwasa (orange) da ke raguwa daga gefen p-n junction (hulɗar zaɓin rami, HSC) zuwa gefen ESC (hulɗar zaɓin lantarki, ESC). Hoto 4h yana ƙara kwatanta halayen masu ɗaukar nauyi a gefen HSC da ESC:
Gefen HSC: ƙananan masu ɗaukar nauyi (ramuka) ana tattara su a ɗan gajeren nesa, ƙarancin yuwuwar sake haɗuwa.
Gefen ESC: ƙananan masu ɗaukar nauyi dole su yi nisa mai tsawo don isa HSC, suna sake haɗuwa sosai a hanya.
Tsarin raba masu ɗaukar nauyi na p-n junction yana da fa'idar biyu na tuntuɓar da aka yi masa nauyi sosai da kuma tuntuɓar da aka wuce, mafi inganci fiye da haɗin high-low mai sauƙi (n-n+).
Bayanan kula: samfurin photovoltage na tsaye yana tabbatar da ƙididdiga cewa "aikin lantarki na gefen p-n junction ya fi na gefen n-n+", kuma yana ba da shawarar "tsawon watsa ƙananan masu ɗaukar nauyi L" a matsayin sabon ma'auni don kimanta asarar gefe.
Hoto 5. Nazarin photovoltage na tsaye na tantanin TOPCon da aka yi ta hanyar rabuwar laser thermal na masana'antu (TLS).
Don a duba ko ƙarshe daga hanyar yankan 45° ya dace da yankan masana'antu, ƙungiyar ta yi amfani da hanyar "thermal laser separation" (TLS) (Hoto 5a) — da farko laser yana shirya gefen p-n junction (Pre-grooving a cikin hoton), sannan ruwan sanyaya yana taimakawa rabuwa. TLS ɗaya ce daga cikin sanannun fasahohin yankan ƙarancin lalacewa a yau. Hoto 5b shine hoton photovoltage na tsaye na TOPCon bayan yankan TLS: gefen hagu (p-n junction) a fili ya fi haske fiye da gefen dama (n-n+). Lissafin ƙididdiga a Hoto 5c ya nuna cewa daga p-n junction zuwa gefen baya, photovoltage har yanzu yana faɗuwa a tsari ɗaya, wanda ya yi daidai da sakamakon yankan 45°.
Muhimmin tabbaci: ko da tare da hanyar TLS na masana'antu (yanka kai tsaye daga gefen p-n junction), photovoltage har yanzu yana nuna yanayin "p-n junction mai girma, n-n+ mai ƙanƙanta". Wannan yana nuna cewa a ƙarƙashin yankan ƙarancin lalacewa, "p-n junction" ba shi ne matsala ba kwata-kwata, amma inda fa'idar take. Ƙwarewar masana'antu ta baya cewa "gefen p-n junction yana aiki mafi kyau" a yankan TLS, a ƙarshe an tabbatar da shi ta hanyar gwaji da ka'ida.
Hoto 6. Nazarin photovoltage na tsaye na sel TBC da THBC, tare da zanen dabarar yankan p-n junction mai ƙarancin lalacewa.
Figures 6a da 6b sune hotunan photovoltage na giciye na sel TBC da THBC. TBC yana da mafi girman photovoltage, 0.39 V, kuma THBC ya ɗan ƙasa kaɗan (0.21 V), amma duka biyun suna nuna fili "haske p-n junction, duhu n-n+" rarraba sarari. Ƙididdigar da aka fitar a Figures 6c da 6d suna bin tsarin Figure 4: raguwa mai sauƙi daga p-n junction zuwa n-n+. Abin da ya cancanci ambaton musamman shine ƙaramin inset a Figure 6c: "rarraba jagora" na photovoltage ga kowane tsarin cell yana nuna tsarin "mai yawa sama-hagu, ƙarancin ƙasa-dama", ma'ana fa'idar lantarki ta gefen p-n junction tana da yawa a cikin tsari da ayyuka. Figure 6e yana bayyana abin da ke sa sel masu baya su zama na musamman: HSC yana tattara ramuka "kusa" a baya, kuma ESC yana tattara electrons "kusa" a baya. Ƙananan masu ɗaukar kaya (ramuka) da aka samar a yankin p-n junction suna buƙatar ɗan gajeren nisa kawai don isa HSC, don haka asarar ta yi ƙanƙanta; ƙananan masu ɗaukar kaya a yankin n-n+ dole ne su yi tafiya mai nisa, don haka asarar ta fi girma. Wannan tsarin ya dace da TOPCon da SHJ daidai. Dangane da duk wannan shaida, ƙungiyar ta ba da shawarar sabuwar dabarar yanke a Figure 6f:
Shawarar masana'antu
A karkashin yanke ƙarancin lalacewa (kamar TLS), ya kamata ku yanka daga gefen mahaɗin p-n. Dalili: gefen mahaɗin p-n yana da mafi girman ingancin rabuwar masu ɗaukar kaya da kuma gajeriyar hanyar jigilar masu ɗaukar kaya. Ko da a ƙarƙashin wasu ɓarnar tsari, yana kiyaye kyakkyawan aikin lantarki. Wannan shawarar tana juyar da al'adar masana'antu ta shekaru ashirin na "guje wa taɓa mahaɗin p-n".
Ra'ayin Ooitech
Gaskiya wannan ɗaya ne daga cikin waɗancan binciken da ke sake rubuta al'adar layi a hankali maimakon ƙayyadaddun taken. Abin da za a ɗauka ga duk wanda ke gudanar da layin n-type: haɗa tsarin yankan laser ɗin ku da ilimin kimiyyar ɗaukar kaya na tantanin halitta, kuma kada ku yi watsi da sanya alamar yankan a gefen n-n+ kawai saboda wannan ita ce tsohuwar doka. Rabuwa mai ƙarancin lalacewa (irin TLS) shine ainihin mai ba da damar a nan, kuma daidaita wannan tsari akan injin yankan laser na hasken rana shine ainihin inda masu yin ƙirar ke samun ko rasa ainihin Voc da FF. Muna gina wuraren yankanmu da haɗawa don rage lalacewar gefen a cikin TOPCon, SHJ da BC formats, don haka irin wannan bincike yana shiga kai tsaye cikin samarwa. Idan kuna son ganin yadda waɗannan matakan suke a kan layi mai gudana, tashar YouTube ta Ooitech a www.youtube.com/ooitech tana da daraja a bi.
