硅异质结太阳电池中钝化层和发射层的优化设计  

Design and optimization of passivation layers and emitter layers in silicon heterojunction solar cells

作　　者：张博宇 周佳凯 任程超 苏祥林 任慧志[1,2,3,4] 赵颖 张晓丹[1,2,3,4] 侯国付 Zhang Bo-Yu;Zhou Jia-Kai;Ren Cheng-Chao;Su Xiang-Lin;Ren Hui-Zhi;Zhao Ying;Zhang Xiao-Dan;Hou Guo-Fu(Institute of Photoelectronic Thin Film Devices and Technology of Nankai University,Tianjin 300350,China;Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin,Tianjin 300350,China;Engineering Center of Thin Film Photoelectronic Technology of Ministry of Education,Tianjin 300350,China;Sino-Euro Joint Research Center for Photovoltaic Power Generation of Tianjin,Tianjin 300350,China)

机构地区：[1]南开大学光电子薄膜器件与技术研究所,天津300350 [2]天津市光电子薄膜器件与技术重点实验室,天津300350 [3]薄膜光电子技术教育部工程研究中心,天津300350 [4]天津市中欧太阳能光伏发电技术联合研究中心,天津300350

出　　处：《物理学报》2021年第18期336-345,共10页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2018YFB1500402);国家自然科学基金(批准号:62074084)资助的课题.

摘　　要：本征钝化层及p型发射层对硅异质结太阳电池的性能具有重要的影响.本文在常规钝化层与晶硅衬底(c-Si)之间插入一层低功率、高氢稀释比沉积的超薄缓冲层,以此来提高钝化效果,并拓宽钝化层工艺窗口.此外,设计并制备了具有宽带隙、高电导特性的重掺杂纳米晶硅/轻掺杂p型双层复合发射极.实验结果表明,双层钝化层具有更加稳定与优异的钝化效果,钝化样品的少子寿命达到4.197 ms,隐含开路电压(implied-VOC,iVOC)达到726 mV.同时双层复合发射层中,轻掺杂的掺杂层可以减弱掺杂剂向本征钝化层的扩散,保证良好的钝化效果,而重掺杂的掺杂层不仅能够提供足够的内建电场,而且可以改善掺杂层与氧化铟锡薄膜的接触特性,进而提升电池的输出特性.并且高氢稀释比的前掺杂层还可以对钝化层起到氢处理的作用,减少钝化层表面的悬挂键,从而增强化学钝化效果,进而提高电池的开路电压.最终,基于商业化制绒的硅片,获得了效率达到20.96%的硅异质结太阳电池,其中开路电压为710 mV,短路电流密度为39.88 mA/cm^(2),填充因子为74.02%.Silicon heterojunction(SHJ)solar cells have attracted much attention in the international photovoltaic market due to their high efficiencies and low costs.The quality of amorphous silicon/crystalline silicon(a-Si:H/c-Si)interfaces of SHJ solar cells has a key influence on the device performance.Therefore,the carrier recombination rate of a-Si:H/c-Si interface needs to be effectively controlled.In addition,as the important component of SHJ solar cells,the p-type emitter must meet the requirements for high conductivity,high light transmittance,and energy band matching with c-Si.The research contents and the relevant achievements of this paper include the following aspects.Firstly,in order to reduce the surface defects and realize the energy band alignment of a-Si:H/c-Si interface,the effect of passivation layer on passivation effect is studied.An ultra-thin buffer layer deposited by a low power and a high hydrogen dilution ratio is inserted between the conventional passivation layer and c-Si to improve the passivation effect and broaden the process window of passivation layer.The effects of the buffer layer thickness and hydrogen dilution ratio on passivation quality are further studied,and the best experimental conditions of buffer layer are obtained.The experimental results show that the sample with double-layered passivation layer is more stable than the conventional passivation layer.The minority carrier lifetime of the sample with single conventional passivation layer is 3.8 ms and the iVOC is 712 mV,while the minority carrier lifetime of the sample with double-layered passivation layer is 4.197 ms and the iVOC is 726 mV.Secondly,for the p-type emitters of silicon heterojunction solar cells,the effects of doping level on the photoelectric properties of p-type hydrogenated nanocrystalline silicon(nc-Si:H)thin films are studied.On this basis,the p^(++)-nc-Si:H/p-nc-Si:H double-layer emitter with wide band gap and high conductivity is designed and fabricated.By analyzing the optical and electrical properties of d

关 键 词：硅异质结太阳电池 钝化层 发射层 复合结构 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TQ127.2[化学工程—无机化工]