Yadda Silver Paste "Ya Cije" poly-Si a Bangon Baya na TOPCon
Teburin Abubuwan Ciki
Gabatarwa
A baya mun yi magana game da man azurfa na gaba. Babban abin a nan shi ne "ƙone shi." Me ya sa laser process guda zai iya sa a maye gurbin dukkan man azurfa na gaba?
Bangaren baya ya bambanta sosai.
Azurfa har yanzu dole ta shiga. Amma da zarar ta shiga, dole ta tsaya nan take.
Domin a gaba, idan azurfa ba ta ƙone ba, juriyar lamba ba za ta ragu ba. A baya, idan azurfa ta ƙone sosai, za ta huda kai tsaye ta cikin mafi darajar ɓangaren TOPCon — passivated contact.
Don haka metallization na gaba ya shafi "yadda ake shiga." Metallization na baya ya shafi "yadda ake tsayawa da zarar ka shiga."
Wannan yanki yana rushe gefen baya gaba daya: me yasa azurfa ke "cizon ta" poly-Si, me ke faruwa da zarar ta yi haka, da kuma yadda sabon bilayer poly-Si zane ke gina wa azurfa hanya da ke cewa "tsaya a kan isowa."
Duba Tsarin Gefen Baya Da Farko
Yadda tsarin baya yake a zahiri
Daga waje zuwa ciki, bayan TOPCon yana tsaye kamar haka: SiNx kariya Layer, (wasu masana'anta suna yin dual-side ALD kuma suna ƙara AlOx Layer a baya ma), poly-Si, tunnel oxide, kuma a ƙarƙashin wannan akwai n-type silicon substrate.
Babban bambanci daga gaba shine wannan Layer na ƙasa — tunnel oxide, kusan 1–1.5 nm kawai kauri. Ita ce hanyar rayuwa ta dukan bayan-gefe passivation. Dukan darajar passivation na poly-Si ya dogara da wannan fim ɗin ya kasance lafiya.
Iyakar aikin azurfa paste na baya ya bambanta da na gaba ma. Ƙonewa ta cikin SiNx kariya Layer ba za a iya tsallakewa ba — wannan ita ce tikitin shiga, kamar na gaba. Amma manufar tuntuɓar sa tana cikin poly-Si. Poly-Si yana da yawan doping, shi kansa Layer ne mai gudanarwa. Da zarar azurfa ta kai poly-Si kuma ta yi tuntuɓa, aikin ya ƙare.
Sannan dole ta tsaya.
Idan azurfa ta ci gaba da gangarowa, ta hanyar oxide na rami da kuma cikin silicon substrate — wucewar da aka rufe ta mutu nan take. Wuraren sake haɗuwa sun bayyana a duk faɗin mu'amala, Voc ya faɗi, kuma tushen wannan tantanin halitta ya lalace.
Bayanan gefe na layin samarwa: wannan AlOx na baya har yanzu ba shi da tilas a yanzu, kuma masana'antoci da yawa suna tsallake shi. Amma yayin da poly finger na baya da sauran tsarin da aka keɓe suke haɓaka, buƙatar kariya a wuraren da ba a haɗa ƙarfe ba za ta ci gaba da hauhawa, kuma yadudduka na kariya na dielectric kamar AlOx za su kasance da muhimmanci a fili. Don haka wani yanki na fim wanda yake kama da 'ba shi da tilas' a yau na iya zama yana ajiye mu'amala don tsarin poly-Si na gaba wanda aka keɓe. Karanta wannan ci gaban, kuma za ka ga ƙirar fim na baya tana share hanya don mataki na gaba.
poly-Si mai Layer Guda — Me Ya Sa Ba zai iya Tsayawa ba
Da farko, yadda azurfa ke 'cizon' hanyar shiga.
Bangaren gaba ya rufe shi: yayin harbawa, azurfa tana narkewa cikin yanayin gilashin da ke narkewa kuma tana tafiya tare da gilashin. A baya, wannan tsarin yana ci gaba da aiki — bambancin shine cewa emitter na gaba yana maraba da azurfa da ke shiga, yayin da poly-Si na baya ba zai iya jure wa azurfa ta shiga zurfi ba.
Matsala da ke tattare da poly-Si mai kauri daya ita ce tsari: an gina shi daga hatsi, kuma iyakokin hatsi suna gudana daga sama har zuwa kasa. Iyakokin hatsi sune babbar hanyar da azurfa ke tafiya da sauri zuwa cikin zurfin poly-Si.
Da zarar azurfa ta gangara tare da iyakokin hatsi ta kai kusa da oxide na rami, tana iya haifar da lalacewa a wurin ko kuma ta samar da hanyar shiga ta karfe, daga karshe ta kai azurfa cikin silicon substrate — kuma daga wannan lokacin, tushen jiki na passivated contact ya ɓace.
Wannan ba hasashe ba ne, abin lura ne da aka rubuta. A cikin takardar 26.66% da aka buga a Nature Energy daga Cibiyar Kayan Aiki ta Ningbo da JinkoSolar, HAADF da HR-TEM sun yi wa fuskar firing na samfurin poly-Si mai kauri daya cikakken bincike na jiki: an ga ƙananan ƙwayoyin azurfa a warwatse a cikin silicon substrate, tare da alamun azurfa suna gudana daga poly-Si har zuwa substrate. Oxide na rami da kansa ya kasance lafiya, amma bai hana azurfa ba — shinge guda ɗaya ba zai iya dakatar da azurfar da ke zubowa tare da iyakokin hatsi ba.
Tsarin Bilayer: Ba Tosa Shi Gaba ɗaya ba, Amma Barin Ƙofa
Bangaren da ya saba wa hankali a cikin mafita na takardar: Maimakon toshe mataccen azurfa, sun gina wa azurfa hanya da ke cewa "tsaya a isowa."
Bayan an yi shi da nau'i biyu na poly-Si, kusan 100 nm duka, kowanne yana yin aikinsa. Wannan yana bayyana tsarin bilayer na musamman da aka yi amfani da shi a cikin takardar. Ba kowane bilayer poly-Si ke bin wannan tsayayyen 60/40 nm, mai nauyi-doped/light-doped ba.
Layer na waje, 60 nm, mai nauyi da doping, galibi amorphous — dakin karba. Yawan iyakokin hatsi, babban sinadarin phosphorus, azurfa tana shiga cikin 'yanci. Da zarar ta kai matsayi, tana samar da lambar ohmic tare da poly-Si mai nauyi da doping. Wannan shine rawar "gudanarwa": dole ne a samar da lamba, dole ne wutar lantarki ta fito.
Layer na ciki, 40 nm, mai sauƙin doping, mai tsananin crystalline — ƙofa. Babban crystallinity, ƙananan yawan iyakokin hatsi, azurfa ba ta da inda za ta je da zarar ta isa nan. Wannan shine tsarin Layer da ke yin "toshewa."
Tunnel oxide — shingen sinadarai na ƙarshe. Ba kawai sirara a jiki ba. Mafi muhimmanci, yana canza yanayin mu'amala don azurfa ta ci gaba da ƙaura zuwa ga silicon substrate kuma ta samar da tsayayyen yanayin ƙarfe. Lokacin da aka dakatar da azurfa kusa da poly-Si mai ƙarancin crystalline da mu'amalar SiOx, samar da hanyar shigar ƙarfe har zuwa substrate ya zama da wahala sosai.
Don haka ainihin "birki" ba wani Layer ɗaya kaɗai ke yin shi ba. Shi ne poly-Si mai ƙarancin crystalline + tunnel oxide tare waɗanda suka zama layin kariya na ƙarshe.
Kwatancen HR-TEM ya bayyana a fili: a cikin samfurin Layer ɗaya, azurfa tana shiga cikin substrate kamar ɗigon da aka warwatsa. A cikin samfurin bilayer, bayan azurfa ta huda mafi yawan Layer na waje, Layer na ciki ya tilasta ta ta zama "siffar kwano" — tana yaduwa a gefe amma ba za ta iya ƙara shiga ƙasa ba.
Tasirin kai tsaye ma: implied open-circuit voltage ya tashi daga 752 mV zuwa 757 mV. Bayan wannan ribar 5 mV akwai muhimmiyar gaskiya ɗaya — an dakatar da shigar azurfa a fili, kuma an kiyaye passivation. Wannan 5 mV ba a "ƙirƙira" shi ba, an cece shi — ƙarfin lantarki da da an rasa shi.
Layin daya don takaita wannan zane: hikimar toshe azurfa ba a cikin “toshewa” ba, tana cikin “sawa” — masu gaisawa suna gaisawa, masu tsaron ƙofa suna tsare ƙofa. Ƙofar waje tana kula da yin hulɗa, ƙofar ciki tana riƙe layin ƙasa, kuma tunnel oxide tana goyon bayan tsayawa ta ƙarshe.
Sakamako, Kuɗi, da Inda Yake Tsaye a Masana'antar
Da farko sakamako: Voc,i +5 mV. Ginshiƙin bayan wannan 26.66% ingancin da aka tabbatar shine daidai wannan tsarin bilayer.
Yanzu kuɗin, kai tsaye: ƙarin ajiya ɗaya, ƙarin mu'amala ɗaya. Ƙarin rikitarwa na tsari da kuɗi gaskiya ne. Kuma takardar kanta ta yarda cewa ƙofar waje ba ta hana 100% na azurfar ba — wannan ƙofa ta ƙarshe tana dogara ne akan haɗin poly-Si na ciki da tunnel oxide.
A kan taswirar masana'antu, wannan ba abu ɗaya ba ne. Ƙaddarar JinkoSolar ta baya ta 26.35% bifacial TOPCon ta yi amfani da daidai tsarin bilayer SiOx/poly-Si tare da UV picosecond laser gyare-gyare na zaɓi. Kuma fiye da ƙungiyar ilimi ɗaya tana aiki akan Bilayered da Triple-layer poly-Si. Sawa na aiki na poly-Si shine alkiblar da masana'antar ke tafiya — a bayansa akwai wannan tunani: raba ayyukan biyu na “hulɗa” da “karewa” daga fim ɗaya, kuma ba da kowanne ga nasa Layer.
Ya cancanci a bambanta a nan: ko da yake suna amfani da bilayer poly-Si iri ɗaya, rikodin biyu na baya-bayan nan suna amfani da shi daban. A cikin takardar Jinko 26.35% (Jami'ar Yangzhou + Jinko, EES), tsarin bilayer ya haɗu da gyaran UV picosecond laser tare da wet etching don zaɓen sirirta poly-Si na waje a yankin da ba a yi ƙarfe ba a baya — manufar ita ce a rage shaƙuwar parasitic da ɗaga bifaciality. Wannan ita ce "matsalar optics." Takardar Ningbo 26.66% tana nufin tsarin bilayer don toshe azurfa da kiyaye passivation. Wannan ita ce "matsalar lantarki." Bilayer poly-Si kamar dandamali ne — ƙungiyoyi daban-daban suna magance matsaloli daban-daban a kai, amma alkibla ɗaya ce: bari kowane Layer ya yi abu ɗaya kawai. A cikin jerin abubuwan da ƙungiyar Ye Jichun ke da su don haɓaka ingancin TOPCon na gaba, tsarin bilayer poly-Si da polysilicon na gida (poly finger) suna kan gaba — wannan Nature Energy takarda kawai ta mayar da abu na farko a wannan jerin zuwa rikodin.
Har yanzu dole a zubar da ruwan sanyi: waɗannan rikodin duk an yi su ne a kan kayan aikin lab, takardun sun faɗi haka da kansu. Daga lab zuwa layin samarwa na yawan jama'a, yawan amfanin ƙasa, lokacin zagayawa, farashi — kowace ƙofa dole a sake share ta.
Tebur ɗaya Don Bayyana Shi
| Abu | Gaban Gaba | Gefen Baya |
|---|---|---|
| Fuskokin Ƙarfe | Fina-finan dielectric da yawa + emitter | SiNx + poly-Si + SiOx |
| Babbar matsala | Azurfa ba za ta ƙone ba | Azurfa tana ƙonewa sosai |
| Gyaran gargajiya | Ƙara aluminum don haɓaka haɗin wutar lantarki | Haɗin kai tsaye na poly-Si mai layi ɗaya |
| Sabuwar matsala | Aluminum yana lalata kariya | Azurfa tana shiga cikin poly-Si |
| Sabuwar mafita | LECO + manna azurfa mara aluminum | poly-Si mai layi biyu |
| Babban ra'ayi | Ƙonewa daidai | Tsayawa daidai |
Layuka uku don komawa da su ga ƙungiyar layin
Na farko, cutar gefen baya da cutar gefen gaba suna bayyana akan sigogi biyu daban-daban. Lokacin da gaba ya yi kuskure, yawanci yana nunawa a cikin FF (juriyar tuntuɓar). Lokacin da baya ya yi kuskure, yawanci yana nunawa a cikin Voc (passivation ya huda). Lokacin da kake neman rashin daidaituwar Voc, ban da duba tsarin passivation, zafin harbi da tsarin poly-Si duk ya kamata su kasance cikin jerin.
Na biyu, nisan da azurfa ke tafiya an ƙaddara shi ta tsari. Harbi kawai yana sarrafa maƙura. Zurfin da azurfa ke shiga — sama shine ƙirar tsarin poly-Si: guda ɗaya ko bilayer, high ko low crystallinity, doping concentration gradient. Taga harbi kawai tana sarrafa gudun akan wannan hanya. Idan tsarin bai ba da layin tsaro ba, duk wani gyaran harbi mai kyau ba zai cece shi ba.
Na uku, yin layi shine yanayin. Kalli tallafin da ke kusa da kyau. Aikin layi na poly-Si, poly finger na baya, AlOx daga zaɓi zuwa wajibi — waɗannan haɓakawa duk suna da alaƙa. Lokacin da kake shirin tsari, kada ka kalli mataki ɗaya kawai, ka kalli inda tsarin ke tafiya.
Don haka ainihin maɓallin inganci a cikin TOPCon metallization ba shine ƙona azurfa da ƙarfi ba, shine sanin inda azurfa ya kamata ta ƙare.
Gaba: bari ta shiga daidai. Baya: bari ta tsaya daidai.
Kuma mataki na gaba shi ne a rage azurfar kanta da ƙaranci.
Ra'ayin Ooitech
Bangaren da yakan cije mu a filin shagon shi ne cewa matsalolin Voc da wuya su samo asali daga maɓalli ɗaya. Voc na baya wanda ba zai murmure ba ko ta yaya ka daidaita taga harbin, yawanci labarin tsari ne, ba labarin manna ba — kuma bilayer poly-Si shine ainihin masana'antar ke yarda da hakan. Ya kamata a tuna waɗannan lambobin har yanzu suna fitowa daga kayan aikin dakin gwaje-gwaje, don haka tsalle zuwa layin gaske shine inda yawan amfanin ƙasa da lokacin zagayowar ke yin magana. Idan kana son irin wannan rarrabewar matakin tantanin halitta, tashar YouTube a www.youtube.com/ooitech tana da ƙarin daga cikin layukan samfuri na gaske.
