Ramuka a cikin Kwayoyin TOPCon: Hanyar Mamaki zuwa Ingancin 26.55%
Teburin Abubuwan Ciki
Bayani
Ga wani abu da ya juya wani dogon zato a cikin silicon PV. Masu bincike sun gano cewa barin wasu 'pinholes' da gangan a cikin SiOx Layer na sel TOPCon na iya tura inganci zuwa 26.55%, maimakon rage shi.
Babban binciken: ƙananan ramuka a cikin tunnel oxide sun rabu zuwa iyalai biyu. Ɗayan shine nau'in sake haɗuwa (oxygen-depleted, inda poly-Si ke tuntuɓar c-Si kai tsaye, mara kyau), ɗayan kuma shine nau'in passivating (oxygen da ya rage yana zama a baya, yana passivating dangling bonds yayin da yake ba da damar tunneling, mai kyau). Nau'in passivating yana auna kusan 1.6 ± 0.2 nm × 1.4 ± 0.3 nm a cikin cross-section, tare da yawan areal na 2 × 10¹² cm⁻². Wani samfurin Fischer ya nuna cewa abin da ke yanke shawarar aikin na'urar ba girman pinhole ba ne, amma ko pinhole an passivate shi.
Maganar: Passivating pinholes don manyan yanki da ingantattun hasken rana na silicon tare da tunnel oxide passivated contact, Nat Commun 17, 2490 (2026). https://doi.org/10.1038/s41467-026-70511-2
Bayanan Bincike da Matsalar da Ta Tsaya
TOPCon yanzu shine babban abin da ake amfani da shi don n-type silicon. Runergy ya kai 26.55% akan 335 cm², Jinko ya tara TOPCon tare da perovskite zuwa 33.24%, kuma single-side n-TOPCon yana da iyakar ka'idar 27.79%. Amma babu wanda ya tabbatar da rawar da ƙananan ramuka a cikin wannan interfacial SiOx layer ke takawa.
Ra'ayin gargajiya: pinhole yana nufin poly-Si ya shiga cikin c-Si kai tsaye, oxygen passivation ta gaza, labari mara kyau.
Gaskiyar ta fi rikitarwa. Oxide yayi kauri sosai (>1.7 nm) yana da kyau a passivate amma yana da wahalar tunneling, don haka FF ya rushe. Oxide yayi siriri sosai (<1.3 nm) yana nufin ƙarin pinholes, kuma yanzu kuna damuwa game da rushewar Voc.
Marubutan sun raba kauri na oxide tare da rarraba iskar oxygen zuwa lokuta uku (sashen Gabatarwa):
Hali na 1: oxide mai kauri, passivation yayi kyau, tunneling bai dace ba
Hali na 2: oxide mai siriri tare da raguwar iskar oxygen, yana haifar da pinholes irin na recombination (pinhole mara kyau na gargajiya)
Hali na 3: oxide mai siriri amma har yanzu iskar oxygen tana shiga cikin pinhole, yana haifar da pinholes masu passivating (sabon binciken nan)
Kafin wannan, ƙudurin HR-TEM bai isa ya ga abubuwa ƙasa da 2 nm ba. Littattafai sun ba da rahoton diamita na pinhole daga 5 nm zuwa 200 nm da yawa daga 10⁶ zuwa 10⁸ cm⁻², waɗanda duk manyan ramuka ne kawai. Selective etching da c-AFM sun dogara da bambancin saurin etching tsakanin Si da SiOx, don haka yankunan da ke da ragowar iskar oxygen ba sa buɗewa ta hanyar etching. Pinholes masu passivating an kawar da su ta hanyar waɗannan hanyoyin. Shi ya sa Hali na 3 ya daɗe ba a gani.
Tsari: Nau'ikan Pinhole Biyu (Hoto na 2)
Aberration-corrected HAADF-STEM (JEM ARM200F plus Spectra 300, 200/300 kV) ya duba poly-Si/SiOx/c-Si interface a kan wafer mai inganci (25.40%) da kuma low-efficiency control (24.07%).
| Type | Yanayin oxygen | Girma (high/low efficiency) | EELS O-K edge |
|---|---|---|---|
| Sake haɗuwa | Oxygen-depleted, poly/c-Si lattice directly joined | Low-efficiency wafer ~1.37 × 1.35 nm | Zurfin oxygen valley |
| Passivating | Residual oxygen present, dangling bonds passivated | High-efficiency wafer 1.55 × 1.25 nm | Oxygen signal still visible, shallow oxygen valley |
Mahimmin batu: pinholes a kan high-efficiency wafer a zahiri suna ƙanana, kuma suna riƙe oxygen da kyau. Duk girman sun fi ƙanana da oda guda fiye da yadda littattafan farko suka ruwaito.
Sakamakon Fischer point-contact model (Fig. 3d a cikin asali):
Yanki na rami mai rami f = πr²/P², amma J₀ ba ya damuwa da f. Abin da ya fi rinjaye shi ne saurin sake haɗuwa a saman S a ramin.
Kusan f ≈ 0.1, da zarar S ≳ 10³ cm/s, J₀ ya tashi da ƙarfi, kuma yana cika sama da S > 10⁵ cm/s.
Ma'ana: mabuɗin babban aiki ba shine "sifili ramuka" ba, shine "ramuka da aka kare". Wannan shine babban haske na takarda gaba ɗaya.
A kan yawa, wannan ɗan juyin juya hali ne. Ƙididdiga daga X-Y orthogonal slicing a kan wafers 40 (high plus low efficiency) sun ba da 2 × 10¹² cm⁻² don karewa da 3 × 10¹² cm⁻² don ramukan sake haɗuwa, 4 zuwa 6 oda na girma sama da ƙimar wallafe-wallafe.
Dalilai uku sun taru: na farko, ra'ayi ya canza, don haka nanodefects karewa da aka riga aka tantance sun zama bayyane; na biyu, samfuran wafers ne na masana'antu da aka inganta sama da 25%, ba tsarin gwaji ba; na uku, hanyar ita ce HAADF matakin atomic, kuma hanyoyin kai tsaye ba za su iya ganin yankin da ke ɗauke da oxygen sub-2 nm ba. Don kare kariya daga haɗuwa tare da jagorar katako daga 50 zuwa 150 nm na samfuran TEM masu kauri, marubutan sun dawo da 4D-STEM ptychography tare da jagorar kauri, suna tabbatar da ƙididdigar yawa ba a gurbata ta hanyar tsinkayar tsinkaya ba.
Wurin Saukowa: Oxidation Mataki Biyu tare da Goge Baya da Haɗin Poly Triple
Masu canji daga Hanyoyin Asali da SI (Tebur na Ƙari 1):
Oxidation mataki biyu: da farko O₂ oxidation zuwa SiO₂ siriri, sannan matakin rashin isashshen oxygen (ba a shigar da oxygen). Nau'in mai wucewa yana buƙatar lokaci mai tsawo na kwararar oxygen, zafi mai girma, kwarara mai girma, da matsi mai girma, wanda ke taimakawa ga oxide mai daidaituwa da yawa.
POCl₃ diffusion: rage zafin ajiya da ɗan gajeren lokaci yana inganta poly crystallization kuma yana hana sake haɗuwa na pinholes.
Siffar goge baya tana gaba da daidaituwar kauri na oxide. Duk ukun dole a daidaita su tare don samar da Case 3 a tsaye.
Kwatanta Ayyuka (Fig. 4 Hard Data)
Samfuran poly-Si/SiOx mai gefe biyu mai daidaituwa (n-Si 1–3 Ω·cm, goge gefe biyu):
τeff: 8.9 ms high efficiency vs 2.96 ms control (injection 5×10¹⁵ cm⁻³)
J₀: 2.6 vs 10.6 fA/cm²
ΔVoc da aka auna a 15.9 mV, amma bambancin J₀ kadai yana bayyana kusan ~11 mV. Sauran ~5 mV marubuta sun danganta ga ingantaccen rayuwar SRH na bulk. Anneal ɗin da aka inganta, yayin da yake haifar da pinholes masu passivating, kuma yana getter ƙarfe impurities (suna ambaton aikin Krügener na 25% POLO). Gyara duka interface da bulk tare shine girke-girke don ketare 25%.
Don FF, bambancin ya fi fitowa daga Rs:
Rs: 357 (high efficiency) vs 619 mΩ·cm² (control), Suns-Voc measured
ρc (TLM): 4.6 vs 5.4 mΩ·cm²
Maganar da ba ta dace ba: ta hanyar tunanin "pinholes masu yawa suna rage ρc", ƙarin pinholes masu passivating a kan wafer mai inganci ya kamata ya rage ρc, kuma hakika 4.6 < 5.4. Amma marubuta sun ƙara wani juyi. Kusa da pinholes na recombination, phosphorus yana yaduwa cikin wafer, yayin da nau'ikan passivating ke toshewa da oxygen (tsarin doping na EDS a cikin Supplementary Fig. 10). Don haka tsarin doping da juriyar lamba suna bin dabaru daban-daban guda biyu, kuma ba za ku iya bayyana su da yawan pinhole kadai ba.
PL ya kasance daidai a duk faɗin wafer, kuma taswirar Corescan na rarraba Voc shima ya riƙe don daidaito na babban yanki.
Layi ɗaya don Masana'antu
Wannan takarda tana tura hanyar sadarwa ta TOPCon daga labari na binary na "oxide mara lahani vs pinhole leakage" zuwa na uku: "pinholes na iya zama masu kyau kuma, muddin oxygen yana nan". Abin da masana'antar ke buƙatar yi na gaba ba shine damuwa game da rashin pinholes ba, amma daidaita tsarin polishing na baya zuwa oxidation zuwa poly deposition domin pinholes su ɗauki oxygen. Wafer na Daheng a 25.40% akan 333.3 cm² ya riga ya tabbatar da hanyar tana aiki.
Ra'ayin Ooitech
Abin da ya ba mu mamaki a nan shi ne yadda wannan ya dogara da tsarin aiki, ba kawai ƙirar tantanin ba. Wannan oxidation mataki biyu, daidaita POCl₃, da polishing na baya duk suna buƙatar tafiya tare shine irin haɗin da ke ɓacewa lokacin da aka haɗa layin gaba ɗaya. A gefen module muna ganin irin wannan tsari, inda lamination da stringing tolerances suke shiru yanke shawarar ko tantanin mai kyau zai riƙe Voc. Idan kuna son kallon kusa kan yadda waɗannan matakan da suka shafi hanyar sadarwa ke canzawa zuwa filin samarwa na gaske, ziyarar mu na masana'anta a YouTube (www.youtube.com/ooitech) sun cancanci biyan kuɗi.
