掺杂非晶氧化硅薄膜中三元化合态与电子结构的第一性原理计算

发布时间：2018-03-10 14:13

本文选题：非晶SiO_x层　切入点：密度泛函理论　出处：《物理学报》2017年18期 　论文类型：期刊论文

【摘要】：基于密度泛函理论和分子动力学方法,研究了ITO-SiO_x(In,Sn)/n-Si异质结光伏器件中非晶SiO_x层的氧化态和电子结构.计算结果表明:具有钝化隧穿功能的超薄(2 nm)非晶SiO_x层,是由In,Sn,O,Si四种元素相互扩散形成的,其中In,Sn元素在SiO_x网格中以In-O-Si和Sn-O-Si成键态存在,形成了三元化合物.In和Sn的掺杂不仅在SiO_x的带隙中分别引入了E_v+4.60 eV和E_v+4.0 eV两个电子能级,还产生了与In离子相关的浅掺杂受主能级(E_v+0.3 eV).这些量子态一方面使SiO_x的性能得到改善,在n-Si表面形成与反型层相衔接的p-型宽禁带"准半导体",减少了载流子的复合,促进了内建电场的建立.另一方面有效地降低了异质结势垒高度,增强了ITO-SiO_x(In,Sn)/n-Si光伏器件中光生非平衡载流子的传输概率,促进了填充因子的提升(72%).
[Abstract]:Based on density functional theory (DFT) and molecular dynamics method, the oxidation state and electronic structure of amorphous SiO_x layer of ITO-SiO / n-Si heterojunction photovoltaic devices are studied. It is formed by the interdiffusion of the four elements in the SiO_x, in which the Innn element exists in the In-O-Si and Sn-O-Si bonding states in the SiO_x grid. The doping of the ternary compounds. In and Sn not only introduces two electron energy levels of EV 4.60 EV and EV 4.0 EV in the SiO_x band gap, but also introduces the two electronic energy levels, Ev 4.60 EV and EV 4.0 EV, respectively. On the one hand, these quantum states improve the performance of SiO_x, and form a p- type wide bandgap "quasi semiconductor" connected with the inversion layer on the surface of n-Si, which reduces the recombination of carriers. On the other hand, the heterojunction barrier height is reduced effectively, the transmission probability of photogenerated non-equilibrium carriers in ITO-SiOx / n-Si photovoltaic devices is enhanced, and the enhancement of filling factor is promoted.
【作者单位】：上海大学理学院物理系索朗光伏材料与器件R&D联合实验室;上海大学材料科学与工程学院;上海大学分析测试中心;
【基金】：国家自然科学基金(批准号:61674099,61274067,60876045) 索朗光伏材料与器件R&D联合实验室基金(批准号:SSE0700601)资助的课题~~
【分类号】：O469

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