SiNx Ya Yi Ƙanƙani Kuma Man Azurfa Ya Huda

Amsa mai sauri: Fim ɗin gaban silikon nitride akan tantanin TOPCon dole ne ya cika buƙatu biyu masu cin karo da juna, kuma kaurin da zai cika duka biyun yana da ƙunci. Layer ɗin SiNx yana aiki azaman murfin rigakafin haske, don haka fim mai kauri yana inganta aikin gani har zuwa wani mataki. Har ila yau dole ne ya jure matakin harbi kuma ya hana man silba ya huda zuwa silikon yayin samar da lamba. Idan an shafa shi da siriri sosai, azurfa tana shiga cikin emitter, yana haifar da gajeruwar hanya; idan an shafa shi da kauri sosai, man ɗin ya kasa samar da lamba mai kyau, yana ƙara juriyar lamba. Kaurin aiki a cikin samarwa yana tsakanin 40 nm zuwa 80 nm, tare da kololuwar harbi kusan 790 °C zuwa 800 °C. Haɗin gwiwar shine dalilin da yasa ake haɓaka tsarin man ɗin da bayanin martabar harbi tare da girke-girken murfi maimakon a ware su.

PV Module Manufacturing · na Jerry, Ooitech

Gabatarwar Samfur

Duk wanda ke gudanar da layin TOPCon tsari ya taɓa fuskantar wannan matsala. Idan ka shafa SiNx da siriri sosai, za ka damu cewa man azurfa zai ƙone ta cikin layin kariya, ya jawo Voc ƙasa. Idan ka shafa shi da kauri sosai, juriya ta haɗuwa za ta tashi, kuma FF ba za ta iya tsayawa ba. Siriri yana ba ka tsoro, kauri ma yana ba ka tsoro — to, nawa ne kaurin da ya dace?

A cikin 2022, ƙungiyar Min Byungsul a ISFH (Cibiyar Binciken Makamashin Rana ta Hamelin, Jamus) ta buga wani bincike a cikin AIP Conference Proceedings wanda ya warware wannan matsala. Sun yi amfani da POLO passivating contacts — sunan ilimi wanda masana'antu ke kira TOPCon, ainihin tsari ne na bakin ciki oxide plus doped polysilicon poly-Si/SiOx — don ware abin da ke faruwa da gaske.

Babban abin da aka fahimta ba shi da rikitarwa: kaurin SiNx da zafin wuta suna da alaƙa. Canza kauri dole ne ka daidaita zafin. Matsar da ɗaya ba tare da matsar da ɗayan ba ko dai Voc ya faɗi ko FF ya rushe.

Ma'aunin Fasaha

Yadda aka kafa gwajin

ISFH ta yi amfani da p-type CZ wafers, tare da n⁺ POLO contact a bayan tantanin (tunnel oxide plus phosphorus-doped polysilicon).

Abubuwa biyu masu mahimmanci:

1. Kaurin rufin SiNx na baya — daga 40nm zuwa 80nm

2. Matsayin zafin wuta — an daidaita tsakanin 790°C da 810°C

Sai suka auna abubuwa biyu: resistivity na lamba ρc (ta hanyar TLM) da sigogin IV na tantanin halitta.

A baya mun kalli takardar JA Solar ta 2016 kan yadda sinadaran sinadarai (rabon Si/N) na gaba SiNx anti-reflection film yake shafar lambar manna azurfa. Wannan aikin ISFH na 2022 yana game da yadda kaurin jiki na baya SiNx capping yake shafar lambar manna azurfa. Haɗa su biyu kuma kun rufe duka bangarori biyu — "sinadaran sinadarai" da "kaurin jiki," fim na gaba da fim na baya.

Duk samfuran an harba su a 800°C, kauri na SiNx na baya ne kawai aka bambanta

Binciken zafin harbi akan samfuran 55nm da 60nm

Fa'idodin Fasaha

Binciken farko: yayi kauri sosai kuma manna ba zai iya harbawa ta ba

Duk samfuran an harba su a 800°C kololuwa, canza kawai kaurin SiNx na baya. Tsarin a bayyane yake daga teburin da ke sama — adadin SiNx da manna zai iya ƙonewa yayin harbawa yana da iyaka. Ketare wannan iyaka kuma manna ba zai taɓa isa ga polysilicon da ke ƙasa ba, don haka juriyar lamba ta tashi.

Hotunan SEM suna ba da shaida kai tsaye:

• 40nm SiNx: manna ya ƙone gaba ɗaya ta cikin SiNx da polysilicon, ya bar yalwa ramukan tsatsa na micron akan poly. An cire polysilicon gaba ɗaya a wurin — kyakkyawar lamba, amma layin kariya ya lalace.

• 80nm SiNx: kawai ƙananan ramukan tsatsa kaɗan, babu wuraren da aka cire poly gaba ɗaya — kariya ta riƙe, amma juriyar lamba ta kusan sau 600 (kusan oda 2.8), kuma FF ta lalace.

Ƙarshen ISFH a bayyane yake: akwai taga SiNx mafi kyau — tsakanin 50 zuwa 60nm. Da yawa sirara, manna ya huda kariya kuma Voc ya ragu. Da yawa kauri, manna ba zai iya shiga ba kuma juriyar lamba ta tashi.

Bincike na biyu: kauri da zafin jiki suna haɗe

ISFH bai tsaya a "50-60nm shine mafi kyau." ba. Sun yi tambaya mafi amfani ga shagon: idan kaurin SiNx ya canza, shin zafin harba yana buƙatar canzawa ma?

Sun zaɓi 55nm da 60nm ƙungiyoyi kuma suka gudanar da binciken zafin jiki daga 790°C zuwa 810°C.

Sakamakon yana da tsabta sosai:

• 55nm SiNx: FF ya kai kololuwa a 800°C, mafi kyawun inganci a can. Ka yi ƙasa kuma haɗin bai isa ba; ka yi sama kuma passivation ta fara wahala.

• 60nm SiNx: FF ya kai kololuwa a 805-810°C. Domin SiNx ya fi kauri, yana buƙatar zafi mafi girma don manna ya harba ta.

A cikin kalmomi masu sauƙi: a ƙarƙashin waɗannan yanayin gwaji, tafiya daga 55nm zuwa 60nm yana canza mafi kyawun zafin harba da kusan 5-10°C. Wannan gangare kawai nuni ne ga tsarin manna guda ɗaya — canza manna kuma kana buƙatar sake daidaitawa.

Bayanan juriyar tuntuɓar sun goyi bayan wannan kuma: yawan zafin jiki, mafi kyawun tuntuɓar - muddin ba ka ketare layin da za ka fara ƙone ta cikin passivation ba.

Hanyar: girman ramin etch shine mabuɗin

ISFH ta yi amfani da SEM don tsara ma'auni mai bayyananne:

• Ramin da ya fi 1μm diamita: poly an cire gaba ɗaya, passivation ta lalace → Voc ya faɗi

• Ramin da bai kai 1μm diamita ba: poly ba a cire gaba ɗaya ba, passivation ta tsaya → juriyar tuntuɓar ta faɗi, Voc bai canza ba

ISFH ta faɗi kai tsaye: "wasu adadin ƙananan ramukan etch ya zama dole don samar da kyakkyawar tuntuɓar. Ramin etch da ke ƙasa da 1μm a diamita da alama ba su da tasiri akan ingancin passivation."

Ma'aunin layi: ramukan etch ba su fi kyau da ƙanƙanta ba, kuma ba su fi kyau da yawa ba - manufa ita ce ƙananan girma, matsakaicin rarraba. Idan ka ga ramuka da yawa >1μm a ƙarƙashin microscope, zafin jiki ya yi yawa ko SiNx ya yi bakin ciki sosai, kuma passivation tana ɗaukar lalacewa.

Aikace-aikacen Samfur

Menene layin samarwa zai iya amfani da shi a zahiri?

1. Kauri na SiNx ba shi da kyau idan ya yi ƙanƙanta, kuma ba shi da kyau idan ya yi yawa. Ƙasa da 40nm, manna yana ƙonewa ta cikin rufin kuma Voc yana raguwa; sama da 80nm, manna ba zai iya ƙonewa ba kuma juriyar haɗuwa ta ƙaru kusan sau 600.

2. Kauri da zafin jiki suna haɗe. Canza kauri na SiNx kuma zafin ƙonewa dole ne ya biyo baya. Bayanan ISFH suna ba da misali — a ƙarƙashin waɗannan yanayi, kowane ƙarin 5nm na SiNx yana motsa mafi girman zafin jiki sama da kusan 5-10°C — amma a sake daidaita bayan canza manna.

3. Ramukan tsatsa alama ce ta "taga". Dubi girman rami da yawa ta hanyar SEM kuma za ku iya tantance ko haɗin kauri-zafin jiki na yanzu yana cikin taga. Yawancin ramuka >1μm → zafi da yawa ko fim ɗin ya yi ƙanƙanta; kusan babu ramuka → sanyi da yawa ko fim ɗin ya yi kauri, haɗuwa na iya zama matsala.

4. Kaurin fim ɗin baya kuma yana sarrafa yawan kyau, da zaɓin manna. Abubuwa uku da ke sama duk sun shafi yadda kauri yake shafar juriyar tuntuɓar da FF ta hanyar wutar da ke wucewa ko a'a. Amma a kan layi, kaurin SiNx na baya yana sarrafa fiye da aikin lantarki.

A cikin samarwa da yawa na gaske, SiNx na baya yawanci ana sarrafa shi a cikin 70-85nm kewayon — mai kauri fiye da 50-60nm "mafi kyawun tuntuɓar" a cikin takardar ISFH. Dalili mai sauƙi: takardar ta auna mafi kyawun tuntuɓar tsantsa don tsarin POLO na musamman da wani manna, yayin da layin samarwa dole ne ya daidaita passivation, tuntuɓar da daidaiton launi gaba ɗaya, kuma ya zaɓi kewayon mai kauri, mafi kwanciyar hankali. Mafi mahimmanci, manna layin kasuwanci yana amfani da tsarin gilashin-frit daban-daban fiye da manna lab na ISFH, don haka taga kaurin SiNx da za a iya ƙonewa ta shima ya bambanta.

Canza kauri kuma ma'anar refractive tana canzawa, kuma launin tsangwama na fim ɗin yana canzawa da shi. Da kauri ko kauri sosai kuma wafers suna nuna bambancin launi, rashin launi da irin wannan raguwar kyau wanda kai tsaye yana yanke yawan kyau. Wannan kuma yana sanya buƙatu mai ƙarfi ga mai yin manna: manna dole ne ya dace da taga aikin fim na baya, ba tilasta fim ɗin baya don ɗaukar wani takamaiman paste ba. Kauri da zafin jiki dole ne su daidaita, kuma paste da kaurin fim dole ne su daidaita — layin tsari ne, ba gyara guda ɗaya ba.

Abubuwa uku da takardar ba ta faɗi ba

1. Dangantaka tsakanin POLO da TOPCon. POLO contact da ISFH ta yi amfani da shi ainihin ultra-thin oxide ne tare da doped polysilicon (poly-Si/SiOx), ainihin iri ɗaya da tsarin baya na TOPCon na yau, don haka sakamakon yana aiki kai tsaye. POLO shine sunan ilimi da ISFH ta gabatar; TOPCon shine kalmar masana'antu; tsari ɗaya ne a zuciya.

2. Samfurin paste yana shafar zurfin shiga. Pastes daban-daban suna da abubuwan glass-frit daban-daban kuma suna iya ƙone ta cikin kaurin SiNx daban-daban. 50-60nm na ISFH ya dogara da wani takamaiman paste — canza paste kuma kana iya buƙatar sake daidaitawa.

3. Doguwar aminci ba a rufe ba. Shin ƙananan ramukan za su girma zuwa manya bayan shekaru 25 na tsufa a waje? Shin za a ƙara lalacewar mu'amala a ƙarƙashin zafi da danshi? Takardar ba ta amsa ba.

Karanta shi tare da JA Solar 2016

Sanya takardun biyu gefe da gefe kuma za ku sami cikakken hoto na tsarin fim ɗin gaba da baya: abubuwan sinadaran suna ƙayyade ko za ku iya haɗawa da kyau, kauri na zahiri yana ƙayyade ko kuna cutar da abin da ke ƙasa yayin haɗawa.

Matsa rabon Si/N na murfin da tsalle-tsallen Rs, FF na rushewa, inganci na faduwa

Tunatarwa ga layin: kada kawai ka zuba ido kan poly yayin neman asarar inganci

With both papers done, back to our own line. When chasing efficiency loss, an engineer's reflex is to first check rear poly thickness, doping level, tunnel oxide thickness — their impact on FF and Voc is well understood and these are standard check items. But the rear SiNx capping layer often gets waved off as a "passivation/cosmetic layer," and few people think of it in terms of contact resistance.

The value of this ISFH paper is exactly that it drags this overlooked variable back onto the table: wrong back-film thickness, paste doesn't fire through or burns through, and FF collapses all the same. Next time you hit a "poly parameters untouched, yet FF mysteriously dropped" situation, don't just circle around the poly — go back and check whether back-film thickness and firing temperature still pair.

Abin lura: Gwajin ISFH ya dogara ne akan harbawa na al'ada. Fasahar LECO da aka karɓa a kan layukan yanzu na iya inganta haɗin gwiwa ta hanyar matakin laser/current na gaba, wanda zuwa wani mataki yana rage hankali ga haɗin harbawa-zafin-kauri — amma kaurin fim ɗin baya har yanzu shine taga tushe kuma ba za a iya watsi da shi ba.

Ra'ayin Ooitech

Muna ganin abu ɗaya akan kowane layin TOPCon da muke kaddamarwa — rufin SiNx na baya ana ɗaukarsa azaman fim ɗin launi kawai, sannan FF yana zamewa a hankali ba tare da kowa ya duba haɗin kauri-zafin ba. Bayanan ISFH sun yi daidai da abin da ke tura mutane zuwa LECO, tunda raba samuwar haɗin gwiwa daga matakin harbawa yana ba da riba ta gaske lokacin da sinadarin frit na manna da taga fim ɗin baya ba su yarda sosai ba. Idan kuna son ganin yadda waɗannan matakan ke gudana akan layin module na gaske — rufi, harbawa, zaren da duka — tashar YouTube ta Ooitech a www.youtube.com/ooitech tana da daraja a bi. Kuma ku tuna wannan nazari ne a matakin tantanin halitta; layin module yana gadon waɗannan sel amma makomar haɗin gwiwa an riga an rufe ta a sama.

Nassoshi

• Min B. et al., AIP Conf. Proc. 2487, 020014 (2022) (DOI: 10.1063/5.0089239)

• Chen X.Y. et al., Solar Energy 126 (2016) 105–110 (DOI: 10.1016/j.solener.2016.01.001)