晏迪博士-多晶硅金属钝化接触是否能成为下一代高效硅电池的主流技术？

Polysilicon pasivated junctions the next technology for silicon solar cells 多晶硅金属钝化接触是否 能成为下一代高效硅电池的主流技 术） Di Yan （晏迪） The department of Electrical and Electronic Enginering 1 2 Our group Group leader Dr. James Bullock Group member Dr. Di Yan Mr. Wei Yan Mr. Jesus Ibara Michel Mr. ShifangWang Main research areas研究课题 Photovoltaic materials 光伏材料 Exploring new materials for solar cels, such as carier-selective passivated contacts and dielectric layers for surface pasivations. Optoelectronic devices（光学器件 2D material basedphotodetectors and transistors Content 3 Introduction Fundamentals about silicon solar cels（硅电池的基本原理） The status of silicon solar cels with poly-Si pasivated contacts（基于poly-Sicontact的硅电池的概述） Poly-Si pasivated contacts technologies（poly-Sicontacts工艺） Diferent approachesPerformances（不同的工艺以及不同工艺的poly-Sicontacts的性能） Industrial aplication（工业化） Current chalenges（现有的挑战） industrial proces combability and cost analysis（现有电池工业的 兼容问题和制造成本） Device architectures（基于poly-Sicontact的电池结构） Conclusion Theoretical values can be achieved by silicon（硅电池的理 论值） J scmax 43.3 mA/cm 2 V ocmax 760 mV V mpp 70 mV Eficiency 29.4 Carier-selective contacts/junction （载流子选择性接触） It is esential have a prefered route for electrons and holes towards opposite metal terminals. Doped siliconsare most comon materials N-type silicon works as electron contact P-type silicon works as hole contact Introduction e - h h h h h h e - h h E Fn E C E V e - h Surface-pasivating “skin” e - e - e - e - e - e - From Cuevas et al. EUPVSEC 2018 electron contact 5 Introduction Thre main carier-selective contacts/junctions（在硅电池里的主要选择 性接触） Dopant Difusion high J o and low ⍴ c ; localised regions stil have high J o . Jo 28 –80 fA/cm2 Poly-Si low Jo and low pc. Jo 6 -20 fA/cm2 A-Si low Jo and TCO required low temperature proces for low pc. Jo 2 –5 fA/cm2 Poly-Si show a high degre of procesing compatibility with conventional dopant difusion technologies.（poly-Si技术跟现有的工业工艺 有很高的兼容性） 6 Introduction The involvement of the poly-Si pasivated contacts can help us to reach higher eficiency silicon solar cels.poly-Si能保证高效的硅太阳能电 池，现在的硅电池的记录保持者都基于poly-Sicontacts） Above 26 on the smal area silicon solar cels ISFH and Fraunhofer ISE 24.9 on the industrial large scale solar cells Jinko solar; The International Technology Roadmap for PV ITRPV predicts that the uptake of poly-Si junction architectures wil continue to grow over the next decade, almost 35 of the entire market, reaching industry average eficiencies of 24 and 24.5 for p-and n-type substrates by the year 2030.（ITRPV展望在2030年将有35的硅太阳能电池将 基于poly-Sicontacts） 7 Poly-Si pasivated contacts technologies Main steps to fabricate poly-Si pasivated contacts （poly-Sicontacts工艺的基本步骤） 1Growth or deposition of a thin interfacial layer, generaly SiO x ;（绝缘层二氧化硅的形成） 2Deposition of a silicon/silicon compound film;（多晶硅薄膜以及硅的化合物的沉积） 3Incorporation of dopants into the silicon film;（掺杂） 4Recrystalization of the silicon and activation of the dopants;（硅薄膜的晶体化以及掺杂的激活） 5Hydrogenation.（氢钝化） Poly-Si pasivated contacts technologies 8 The Jo and its coresponding VULof poly-Si contacts with diferent approaches. 在不同工艺下的复合电流以及其对应的理想开压） Jo 735 mV was achieved for poly-Si contacts using a range of aproaches. Independent of the deposition/doping technique used. （性能在不同的工艺环境下表现的很稳定） Majority data are on the LPCVD with ex-situ thermal oxide and subsequent thermal difusion proces. This is widely used in industries. （研究 主要集中于产业化的LPCVD和热扩散的工艺） A consistent trend of lower J 0 for phosphorus- doped, versus boron-doped. Due to the segregation and difusion coeficients of dopants in poly-Si layers and the SiOxlayers. （n型比p型 有较低的复合电流） 9 Industrial perspectives TheimpactofthethicknesonJsc厚度对于光学 性能的影响） Increasingpoly-SithicknessesincreasesJ sc loses duetoits“parasiticabsorption”. J sc of0.4-0.5mA/cm 2 per10nmforfront. 0.3-0.5mA/cm 2 fora140nmthickpoly-Silayer asrearside. Usingwidebandgapmaterials,e.g.SiCxorSiOx. Theimpactofscreen-printedmetallization proces（金属接触对于复合的影响） TendstohavehighJoaftermetalizationproces, 100timeshigher. Metalpasteand/orusingothermetalization methods,e.g.plating. Theimpactofsurfacetexturing（硅表面对于复 合的影响） TheJoofpoly-Sijunctionsontexturedsurfaces isapproximately10timeshigherthanthaton planar100surfaces. Aslightofetchingoftipsandoptimizingthe oxidegrowthanddopingprofiles. 10 Industrial perspectives According to a recent study by Kafleet al., the cost of an n-type solar cel a rear n poly-Si layer is 18 higher than a p-type PERC cel. （poly-Sin型电池的成本比 p型PERC电池的成本高18） In adition to the costs of boron difusion and LPCVD Si film deposition, which are relatively low, the cost diference is mainly due to the use of n-type wafers instead of p-type and to the cel’s metalisation.（主要 的成本来源于金属化和n型硅片） In terms of /W, this cost gap can be compensated for if PV modules made with poly-Si junctions have at least a 0.4 higher conversion efficiency than conventional PERC modules.（但是高效的poly-Si的n型 的成本 接 于p型PERC的 ） 11 Future perspectives device architectures Tandem solar cells（ 于硅电池的 电池 ） Poly-Si contacts have excelent thermal stability. 较 的热稳定性） Posibilitiesofusingother metal oxide contacts in combination with poly-Sitoformthe “recombination layer”, which both simplifies the fabrication and reduces parasitic absorption（在 成 电池中的 复合 于 材料 合的 能性 C 的应 ） Single junction solar cels（ 硅电池） IBC P-type PERC celswithrearjunction（ 的p型PERC 电池） N-type solar cels（n型 面电池） P-type solar cels with localised poly-Si contacts（p型 电池 的poly-Si on ） 12 Conclusion Siliconsolarcellarchitecturesfeaturingpoly-Sibasedjunctionsarepoisedtobecomethenextevolutionarystepfor mainstreamsiliconphotovoltaics,pavingthewaytowardsanaverageindustrycellefficiencyof25overthenext decade.（poly-Sicontact技术将是下一代25转换效率的硅电池主流技术） Thelargelyuniformresultsacrosmultiplepoly-Sifabricationproceduresspeakstotheversatilityoftheapproachand thepotentialfortransfertolow-costtechniques,whichhasbecomeadominantresearchfocus.（poly-Sicontact对 于不 工艺的 性 下一步的工艺研究 将 以 成本 主要 ） However,severalchallengesremaintobemet,mostassociatedwiththecostandperformanceofpoly-Sijunction metalization.Thesechallengesarelargelyresponsibleforthecurent18highermanufacturingcostofpoly-Si junctioncellscomparedtoPERC.（ 很多的 成本高于现有的 技术 化 光学性 是下一步的研究 ） Severalcandidatecellarchitecturesarebeingexploredwithbothnandp-typesubstrates,mostofwhichoffera1 absoluteliftinefficiencyoverthecurentindustrydominatingPERCtechnology.（poly-Sicontact⁄ 多的电 池的ƒ的currency1性 效率将“现有的 电池的效率高） Poly-SijunctionsprovideapathwayforupgradingcurentPERCtechnology,anditislikelythatoverthenextdecade botharchitectureswilldevelopfurther,alongsideothersolarcelltechnologies.（poly-Si技术将是 技术的‹› fi 不fl的将 跟 –电池技术†‡在光 ） Thankyou谢谢 Email di.yanunimelb.edu.au