Gabatarwa

Monocrystalline N-type TOPCon solar cells sun zama ɗaya daga cikin mafi kyawun fasahohin inganci a masana'antar photovoltaic. Samar da su ya ƙunshi dogon jerin matakai da aka sarrafa a hankali, ciki har da texturing, boron diffusion, laser SE, annealing, alkaline polishing, PE-poly, annealing, RCA cleaning, coating, metallization da gwaji da rarrabuwa na ƙarshe. A cikin wannan labarin, muna tafiya ta kowane babban matakin tsari kuma mu bayyana dalilin da yasa yake da mahimmanci.

1. Rubutun (TEX)

Manufar Rubutun

Manufar rubutun shine cire layin lalacewa na inji a saman wafer da kuma samar da saman rubutun mai siffar dala wanda ke kara daukar haske. Ta hanyar rage haske mai haske, ana inganta gajeren kewaye (Isc), wanda a karshe yana kara ingancin canza wutar lantarki na tantanin halitta.

Wet etching shine babban tsarin rubutun a yau. Ions na karfe, layukan lalacewa da sauran gurbacewa a saman wafer suna aiki a matsayin cibiyoyin sake hadewa. Tunda dole ne electrons da ramuka da aka raba su yi tafiya a kan saman wafer kuma a tattara su, wadannan cibiyoyin sake hadewa suna rage rayuwar dan kadan, yana sa masu daukar kaya su sake hadewa kafin a iya fitar da su a matsayin wutar lantarki na waje. Layukan oxide na saman da gurbacewar kwayoyin halitta suma suna shafar ingancin ajiya da passivation na AlOx da SiNx, don haka tsaftace saman sosai yana da mahimmanci kuma yana shafar ingancin tantanin halitta kai tsaye.

Ka'idar amsawa

Rubutun yana dogara ne akan kaddarar anisotropic etching na silicon crystalline, inda alkali mai ƙarancin taro da abubuwan ƙara suke etching daban-daban crystal orientations a farashi daban-daban. Matsakaicin etch akan jiragen (110) da (100) ya fi girma fiye da akan jirgin (111). Bayan wani lokaci na etching, an bar tsarin "pyramid" guda huɗu da suka haɗa da jiragen (111) a saman wafer monocrystalline.

Tsarin atomic ya bambanta a cikin jiragen crystal, yana haifar da farashi daban-daban na etch:

• Jirgin (100): tsarin atomic yana da ɗan sako-sako tare da ƙarin haɗin sinadarai da aka fallasa, yana ba da mafi saurin etch.

• Jirgin (110): yawan atomic tsakanin (100) da (111), tare da sauri amma ɗan ƙaramin etch fiye da (100).

• Jirgin (111): tsarin atomic mafi matsewa, tare da haɗin sinadarai da wuya a kai hari, yana ba da mafi jinkirin etch.

Matsayin Abubuwan Ƙara Rubutu

Additives suna rage tashin hankali na silicon, suna inganta sakin kumfa na hydrogen da aka kafa yayin amsawa, kuma suna sa pyramids su zama daidai. Suna inganta jika tsakanin farfajiyar wafer da maganin amsawa, suna raunana ƙarfin etching na NaOH, suna ƙara wuraren nucleation da yawa, kuma suna inganta samar da adadi mai yawa na ƙananan pyramids. Gabaɗaya, kaddarorin additive suna da tasiri kai tsaye a kan farfajiyar textured pyramid.

Tsarin Aiki

Tsarin texturing yawanci ya haɗa da: tsaftacewa ta farko tare da NaOH da H2O2 (tare da ultrasonic tsaftacewa a 60°C, sannan a wanke da ruwa mai tsabta) don cire kwayoyin halitta, ƙazanta na ƙarfe da lalacewa; alkaline texturing ta amfani da kusan 0.6% NaOH da 0.4% additive a 82°C na daƙiƙa 420 don samar da pyramid texture; tsaftacewa bayan aiki don cire ragowar kwayoyin halitta; tsaftacewa da acid ta amfani da dilute acid (3.15% HCl + 7.1% HF) don kawar da ragowar alkali da cire oxide Layer; jinkirin cirewa pre-dehydration don cire ruwan fim ta hanyar tashin hankali; kuma a ƙarshe bushewa da iska mai zafi 90°C.

2. Boron Diffusion (B Diff)

Manufa

A ƙarƙashin zafin jiki mai girma, atom ɗin boron suna yaduwa zuwa saman wafer N-type don samar da haɗin PN. Filin da aka gina na haɗin PN yana raba masu ɗaukar hoto da aka samar don fitar da wutar lantarki a waje. Wafer P-type, tare da babban taro na ramuka, suna amfani da doping phosphorus don samar da haɗin; Wafer N-type, tare da babban taro na electrons, suna amfani da doping boron.

Ka'idar Tsari

Boron trichloride (BCl3) yana wucewa ta bututun quartz a 800-900°C kuma yana amsawa da oxygen don samar da B2O3, wanda ke ajiyewa a saman wafer tare da iskar nitrogen kuma yana amsawa da Si don samar da atom ɗin boron, yana samar da Layer borosilicate glass (BSG). Atom ɗin boron sannan suna yaduwa cikin wafer don samar da haɗin PN. BCl3 ruwa ne mara launi mai hayaƙi ko gas mai nauyin 1.35 kg/m3, wurin narkewa -107.3°C da wurin tafasa 12.5°C. Ba mai ƙonewa ba ne, mai haushi da ƙamshi, yana rushewa cikin ruwa don samar da hydrogen chloride da boric acid tare da sakin zafi mai yawa. Samfurin tsaka-tsaki B2O3, mai wurin narkewa 450°C da wurin tafasa 1860°C, yana zama ruwa a duk tsari kuma yana da ƙarfi ga abubuwan quartz.

Yaduwar boron ya fi wuya fiye da yaduwar phosphorus, don haka hanyar TOPCon tana sanya buƙatu mafi girma akan kayan aiki, gami da daidaito mafi girma, yanayin zafi mafi girma (yawanci sama da 1000°C) da lokutan yaduwa masu tsawo (samar da fim yakan ɗauki har zuwa mintuna 240), wanda ke ƙara farashin kayan aiki da samarwa a matakin samar da junction.

Tsarin Aiki

Ana gudanar da yaduwa ta hanyoyi biyu. Yaduwar pre-deposition (matakin ajiyar BSG) tana amfani da ƙananan zafin jiki kuma tana kiyaye wafer a cikin yanayi mai cike da ƙazanta, don haka yawan ƙazanta a saman yana tsayawa; wannan ana kiransa yaduwar tushen saman akai-akai. Yaduwar redistribution tana tura boron daga BSG zuwa cikin wafer a yanayin zafi mafi girma a cikin yanayi mai wadatar oxygen ba tare da ƙazanta na waje ba; a nan yawan ƙazanta a saman yana canzawa da lokaci, wanda ake kira yaduwar tushen saman iyaka, tare da rarraba Gaussian na ƙazanta.

Matakan aiwatarwa na yau da kullun sune: yin famfo na vacuum don kaiwa ga ƙananan matsa lamba; dumama zuwa zafin yaduwa (800-900°C); riƙe zafin yayin da ake ƙara rage matsa lamba; gano zubewa a ƙarƙashin ƙananan matsa lamba; pre-oxidation don samar da SiO2 Layer na 1nm don rage saurin mataki na gaba na yaduwa da kuma sa boron yaduwa ya zama mafi daidaito; yaduwa/deposition ta hanyar shigar da tushen boron don aiki mai aiki da kuma shigar da shi; ƙara dumama sama da 900°C don ƙara yawan yaduwa da zurfi; post-oxidation don samar da SiO2 Layer sama da 100nm don sarrafa abun ciki na boron, zurfafa junction, samar da Layer mai kariya da kuma cire ƙazanta daga substrate; sanyaya zuwa zafin buɗe bututu mai aminci; da kuma karya vacuum tare da N2 don maido da matsa lamba na yanayi.

3. Cire BSG da Alkaline Etching

Cire BSG

Bayan yaduwar boron, bayan wafer da gefuna suna ɗauke da BSG Layer mai kauri (40-100nm oxide). Wannan Layer na gilashin borosilicate yana cutar da matakai na gaba kuma yana iya haifar da zubewar PN junction, don haka ana buƙatar etching da tsaftacewa na sinadarai bayan doping. Kafin alkaline etching, tsarin HF na gefe ɗaya na layi yana cire BSG na baya da gefuna, yayin da BSG na gaba ana kiyaye shi azaman abin rufe fuska yayin alkaline etching don kare tsarin gaba.

Wafer ɗin ya fara shiga cikin kayan aikin tsabtace HF na layi, inda kusan 60% HF ke narkar da BSG na baya zuwa cikin ruwa yayin da fim ɗin ruwa ke kare BSG na gaba, sannan kuma ana wanke shi da ruwa mai tsabta na kusan minti 0.5. Jerin ya haɗa da: shafa fim ɗin ruwa ta amfani da hydrophilicity na SiO2 don kare BSG na gaba; etching HF na baya da gefen BSG; matakin ruwa don sabunta fim ɗin ruwa mai yuwuwar gurɓata; wanke ruwa don cire ragowar HF; tsabtace acid don cire ragowar ions; da bushe fim ɗin ruwa na gaba.

Etching Alkaline

Manufar etching alkaline shine cire haɗin PN a baya da gefuna don hana zubar da ruwa, da kuma samar da siffa mai daidaituwa, tsabta a baya don shirya don passivation na baya.

Akwai hanyoyi guda biyu. Rubutun na biyu yana kama da na farko, amma abin da ake ƙarawa dole ne ya rage saurin amsawa tsakanin BSG da alkali. Goge alkaline yana amfani da alkali mai yawan gaske da abubuwan ƙarawa don hanzarta amsawar alkali-silicon, raunana halayen anisotropic etching da samar da siffar goge mai kyalli. Abin ƙarawa na alkaline etching yana kare BSG na gaba, yana rage saurin amsawarsa da alkali don hana wuce gona da iri, yana kiyaye BSG a matsayin abin rufe fuska don matakai na gaba, yana rage tashin hankali don sakin kumfa na hydrogen, yana inganta jika da ƙara yawan nucleation.

4. Ajiya da Rufi

Wannan mataki yana ajiye Tunnel Oxide (TOX), Poly-Si Layer da Mask. Ajiya yana faruwa ne a cikin yanayin tururi mara iska kuma ana iya raba shi zuwa Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD) da Atomic Layer Deposition (ALD). PVD yana tursasa tushen abu zuwa atom, kwayoyin halitta ko ions kuma ya ajiye shi a kan substrate a ƙarƙashin ƙarancin matsi; CVD yana samar da ajiya ta hanyar halayen sinadarai a kan substrate; kuma ALD yana ajiye abu Layer ta Layer a matsayin guda ɗaya na atomic.

Tunnel Oxide Layer (TOX)

Tunnel oxide layer yana dogara ne akan tasirin quantum tunneling, yana amfani da oxide mai sirara sosai (yawanci 1-2nm) a matsayin shinge. Tsakanin n-type silicon substrate da doped poly-Si Layer, yana ba da damar jigilar masu zaɓe: electrons (mafi yawan masu ɗauka) suna tunnel ta cikin oxide zuwa cikin poly-Si Layer, yayin da ramuka (ƙananan masu ɗauka) suna fuskantar babban shinge mai tsayi (kimanin 4.5-4.8eV) kuma ana toshe su. Hakanan yana haifar da lanƙwasa band da field-effect passivation, inda bambancin aikin aiki tsakanin doped poly-Si da substrate ke lanƙwasa makamashin band na interface kuma ya samar da filin electrostatic wanda ke ƙara yawan masu ɗauka kuma ya kori ƙananan masu ɗauka, yana ƙara rage haɗuwa a interface.

Ana iya shirya oxide ta hanyar thermal oxidation (mai jituwa da LPCVD) ko ta PECVD, PEALD da thermal oxidation (mai jituwa da PECVD). Dangane da yawan fim, PEALD yana ba da mafi kyawun passivation amma a farashi mafi girma na kayan aiki, yayin da thermal oxidation da PECVD ke ba da ingantaccen tattalin arziki. ALD yawanci yana ba da kusan 0.7nm, thermal oxidation kusan 1.3nm, kuma tsarin tunneling gabaɗaya yana samuwa a kaurin da ke ƙasa da 1.6nm. LPCVD ya fi girma, yana da fa'idodi kamar sauƙin sarrafawa da ingancin fim mai girma, amma yana iya samar da wani nau'in doped poly-Si layer a gefen gaba wanda dole ne a tsaftace shi, kuma yana da jinkirin fim. PECVD poly-Si sabuwar fasaha ce mai saurin ajiya, doping a wurin da ƙananan wrap-around, amma balagaggen ta har yanzu yana buƙatar ingantawa kuma yana iya fama da ƙura, babban abun ciki na hydrogen da samuwar kumfa yayin annealing mai zafi.

Poly-Si Layer

Polycrystalline silicon (Poly) an yi shi da ɗimbin ƙananan hatsin silicon, girman hatsi yawanci daga dubun zuwa ɗaruruwan nanometers da iyakokin hatsi a tsakaninsu. Poly-Si layer yawanci ana yin phosphorus doping don samar da n-type poly-Si mai yawan doping, yana inganta conductivity, yana ba da damar carrier-selective transport da kuma samar da kyakkyawar hulɗar ohmic tare da substrate.

Shirye-shiryen Poly-Si ya ƙunshi duka ajiya da doping. Ajiya yafi amfani da LPCVD ko PECVD tare da kauri kusan 100-150nm; fim ɗin amorphous yana canza crystallinity yayin annealing, yana canzawa daga gauraye microcrystalline-amorphous zuwa polycrystalline da kunna passivation. Don doping, LPCVD yawanci yana ajiye intrinsic poly-Si Layer farko sannan ya kammala doping phosphorus ta hanyar tanderun watsawa ko ion implantation (ex-situ doping), tunda doping yayin jinkirin ajiyar LPCVD zai kara jinkirta shi. PECVD yana da ingantaccen fim kuma yana iya kammala doping phosphorus yayin rufi (in-situ doping). LPCVD, babbar fasaha don poly-Si, tana aiki ta hanyar lalata silane (SiH4) ta zafin jiki zuwa atom ɗin silicon waɗanda ke ajiye su cikin fim. Lura cewa poly-Si mai kauri yana haifar da asarar FCA (parasitic) mai tsanani da asarar gajeren kewayawa mai girma, kuma yawan doping phosphorus yana ƙara ɗaukar FCA da asarar halin yanzu.

Mask Layer

Layer na mask yawanci shine fim na SiO2 mai kauri kimanin 10nm wanda ake girma bayan ajiyar poly-Si don kare tsarin baya, musamman hana hanyoyin jika na gaba daga cizon layer na poly-Si. Don tabbatar da cewa tsarin baya bai lalace ba a cikin kayan aikin jika na tanki, bayan aikin poly ana girma SiOx mask (kimanin 10nm) a saman baya ta amfani da silane da nitrous oxide (lura: silane da oxygen suna da haɗarin fashewa a wuraren da ba na vacuum ba).

Matakan aikin sune: dumama a cikin vacuum don kawo wafer zuwa zafin da ake buƙata; ajiyar farko na tushen silicon mara nauyi (gas kawai, babu RF, don cika bututu daidai da daidaita matsa lamba); ajiyar tushen silicon mara nauyi (RF a kunne, don ajiye fim mara nauyi wanda zai toshe da kuma buffer phosphorus daga poly mai nauyi); ajiyar farko na tushen silicon mai nauyi (gas kawai); ajiyar tushen silicon mai nauyi (RF a kunne, don ajiye fim na poly mai ɗauke da phosphorus); samar da mask na oxide ta hanyar PECVD SiOx; da kuma share N2/Ar don fitar da SiH4 da N2O daga bututu don hana konewa lokacin buɗe ƙofar tanda.

5. Annealing

Manufar annealing shine don canza silicon amorphous da PECVD ya girma zuwa silicon polycrystalline, kunna atom na phosphorus da kuma ciyar da zurfin junction, da kuma samar da pinholes. Tsarin yana gabatar da BN2 (boron nitride) kuma a hankali yana dumama zuwa 890-920°C, inda ake tura BN2 a babban zafin jiki don kunna atom na phosphorus a cikin poly film da samar da ingantaccen doping.

Akwai dangantaka tsakanin annealing da TOX: tare da tunnel oxide ba canzawa, haɓaka zafin annealing yana samar da ƙarin pinholes da in-diffusion, rage contact resistivity da inganta FF yayin da har yanzu yana biyan buƙatun passivation; a daidai zafin annealing, tunnel oxide mai kauri yana samar da ƙarin pinholes da in-diffusion da kuma mafi girma saturation current.

6. Cire PSG da Tsabtace RCA

Yayin da ake yin PEALD na n+-poly-Si film, wani yanki na n+-poly layer yana samuwa a gaban wafer, wanda aka rufe da siririn Mask (SiOx) film. HF na gefe ɗaya yana cire SiOx, sannan wani alkaline bath yana cire n+-poly-Si na gaba. Wafer yana wucewa ta cikin tankin etching, tankin alkaline da tankin tsaftacewa don halayen sinadarai kafin bushewa.

Manufar RCA shine cire kewayen plating da yin etching gefe don hana zubewa daga gefe, da kuma tsaftace wafer ta hanyar cire BSG na gaba da baya da mask ɗin da bushewa don shirya fina-finan kariya na gaba da baya. Tunda poly shine silicon polycrystalline, cire kewayen yana amfani da alkaline polishing tare da high-concentration alkali da additives.

Additives na RCA suna tsaftace abubuwan inorganic da ragowar samfura don inganta jika saman, aiki azaman masu kara kuzari don hanzarta haɗin OH- da silicon da hanzarta cire kewayen da etching gefe, da rage yawan alkali etching na silicon dioxide don kare BSG na gaba da mask na baya daga yawan etching.

Matakan aiki sune: inline HF don cire PSG da aka kafa a gaba da gefuna bayan N2 annealing yayin da ake kiyaye PSG na baya don kare poly na baya; alkaline polishing tare da NaOH da additive don cire poly na gaba da gefe da yawa; wanke alkaline don cire ragowar additives da ƙazanta; tsaftace acid don neutralize ragowar alkali da cire ions na ƙarfe; jinkirin cirewa ta amfani da ruwan deionized na daki tare da robot don hana alamun ruwa; da bushewa a 90°C don hana ragowar ruwa a kan wafers da masu ɗauka.

7. ALD (Atomic Layer Deposition)

Atomic layer deposition yana rufe kayan a matsayin guda ɗaya atomic layers akan substrate kuma ana siffanta shi da yanayin kai-tsaye, wanda shine tushen ALD. Ta hanyar lokaci ko sarari, substrate yana fallasa ga daban-daban precursors. Lokacin da substrate yake cikin yanayin precursor A, A yana haɗuwa da sinadarai a saman har sai ya cika, sannan ya tsaya; idan aka fallasa ga precursor B, B yana amsawa da A da aka riga aka haɗa, yana samar da abubuwan da suka biyo baya har sai an cinye precursor na farko gaba ɗaya kuma amsawar ta tsaya kai tsaye, tana samar da atomic layer da ake buƙata. ALD tana maimaita wannan amsawar don gina fim ɗin da ake so.

A bayan wafer, AlOx passivation yana rage yawan sake haɗuwa a bayan. Aluminum oxide yana ɗauke da tsayayyen caji mara kyau wanda yake a daidai inda aluminum oxide da silicon oxide suke a saman wafer; wannan babban yawan caji mara kyau yana tabbatar da ingantaccen filin passivation. Aluminum oxide kuma yana ba da kyakkyawan sinadari passivation, yana cika dangling bonds a saman crystalline silicon kuma yana rage yawan yanayin interface.

Matakan aiwatarwa sune: pre-deposition (gas kawai, babu RF, cika bututu daidai da daidaita matsa lamba, a kiyaye gajarta don guje wa sharar gas da haɗari); deposition (RF a kunne, tare da TMA yana samar da plasma wanda ke amsawa da saman don samar da AlOx, sannan inert gas purging, maimaita har sau 40); da Ar purging don tura TMA da O2 daga bututu don hana konewar TMA lokacin buɗe kofar tanderun.

8. Gaban da Bayan Silicon Nitride (SiNx)

Rufin SiNx yana da dalilai da yawa. Yana kare fuskar tantanin halitta, tunda silicon nitride yana da ƙarfi sosai wanda yake jure har 1200°C, kyakkyawan juriyar lalacewar sinadarai ga kusan dukkanin inorganic acids da NaOH kasa da 30%, kuma shine babban insulator na lantarki. Yana ba da anti-reflection, tare da mafi kyawun refractive index na 1.96 a cikin iska; ƙara yawan silicon yana ƙarfafa surface passivation, kuma littattafan sun ba da rahoton saurin sake haɗuwa da saman yana faɗuwa ƙasa da 20cm/s a refractive index na 2.3, tare da mafi kyawun bulk passivation tsakanin 2.1 da 2.3. Hakanan yana hana oxidation ta hanyar tsarinsa mai yawa. TOPCon front emitter passivation galibi yana amfani da aluminum oxide da SiNx:H film, yayin da rear passivation galibi yana amfani da poly-Si.

Hanyar kariya ta SiNx tana aiki ta hanyoyi biyu. Kariyar sinadarai tana rage yawan lahani a mahaɗin ta hanyar rage ƙwayoyin da ba su da alaƙa, ko dai ta hanyar shuka wani saman Layer wanda ke ba wa atom isasshen lokaci da kuzari don cika ƙwayoyin da ba su da alaƙa, ko kuma ta hanyar ajiye wani fim mai arzikin hydrogen dielectric da sakin hydrogen yayin sintering don ya haɗu da ƙwayoyin da ba su da alaƙa. Kariyar tasirin filin tana rage yawan masu ɗaukar ƙananan da ke isa saman ta hanyar samar da filin lantarki kusa da saman wanda ke korar masu ɗaukar nauyi iri ɗaya, wanda ake samu ta hanyar rage yawan tattara sinadarai a saman ko ƙara wani dielectric Layer mai ƙayyadaddun caji.

Matakan tsarin SiNx sune: pre-deposition (gas kawai, babu RF, cika bututu da daidaita matsa lamba); deposition 1-2-3 (RF a kunne, shigar da SiH4 da NH3 don samar da SiNx Layer uku tare da raguwar rabon Si-N a hankali, tunda babban rabon Si-N yana ba da babban refractive index); deposition 4 (RF a kunne, SiH4, O2 da NH3 suna samar da SiONx Layer); deposition 5 (RF a kunne, SiH4 da O2 suna samar da SiO2 Layer); da N2 tsarkake layukan da bututu don cire gas mai amsawa da hana fashewar SiH4 lokacin buɗe ƙofar tanderun.

9. Screen Printing (Metallization)

Bayan an gama texture, diffusion da coating don kammala PN junction da passivation, tantanin zai iya samar da wutar lantarki a ƙarƙashin haske. Don fitarwa da tattara wannan wutar, ana buga na'urorin gaba da baya a saman tantanin, yawanci ta hanyar screen printing, bushewa da sintering.

Tsarin screen printing ya ƙunshi abubuwa biyar: squeegee, tawada (paste), allo, substrate (wafer) da dandamalin bugu. Aikin bugu mai dacewa (viscosity, ikon shear-thinning) shine sharadi na farko don bugu mai yawa, kuma yawan raga, diamita na waya da faɗin layin da aka tsara suna ƙayyade siffar da aka buga. A cikin aiki, tawada yana wucewa ta cikin buɗaɗɗen allo, kuma squeegee yana matsa lamba yayin motsi a kan allo, yana matsa tawada daga buɗaɗɗen allo zuwa wafer. Viscosity na tawada yana sa shi manne a cikin iyaka, kuma squeegee yana kula da lamba madaidaiciya tare da allo da substrate, layin lamba yana motsawa tare da squeegee don kammala bugun.

Manne dole ne ya ba da kyakkyawan bugu don samar da yawa, kyakkyawar hulɗar ohmic tare da emitter don ƙarancin juriyar hulɗa da mafi girman FF, ƙarancin lalacewa ga emitter don iyakance asarar Voc da ke haifar da ƙarfe, da mafi ƙarancin juriyar taro don rage asarar halin yanzu. Matakan aiki sune: bushewa don ƙafe kwayoyin halitta a cikin manne; pre-sintering don narke gilashin frit, narke barbashi na azurfa da buɗe Layer na passivation; sintering don narke ƙarin ƙarfe a cikin gilashin da haɗa shi tare; da sanyaya don ƙarfen da aka narke a cikin gilashin ya yi hazo a saman, yana samar da hulɗar ohmic tsakanin ƙarfe da semiconductor.

Ƙarshe

Tsarin masana'anta na TOPCon jerin matakai ne na musamman na rubutu, doping, passivation, ajiya, annealing da metallization, kowanne an ƙera shi don haɓaka zaɓin mai ɗauka da rage sake haɗuwa don ingantaccen canji.

Ra'ayin ooitech: ooitech ta yi imanin cewa babban ingancin TOPCon ya fito ne daga haɗin gwiwar tunnel oxide da fasahar tuntuɓar passivated, inda kowane tsafta, ajiya da annealing ke aiki tare don tura iyakokin zaɓin mai ɗauka da passivation na saman.