A technique for field effect surface passivation for silicon solar cells
A technique for field effect surface passivation for silicon solar cells
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DOI：
10.1063/1.4882161
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发表时间：
2014-06-09
影响因子：
4
通讯作者：
Wilshaw, Peter R.
中科院分区：
文献类型：
--
作者：
Bonilla, Ruy S.;Wilshaw, Peter R.
电荷载流子在半导体表面的复合是光电器件（特别是太阳能电池）效率的主要限制因素。这种复合的减少（通常称为表面钝化）是通过经由化学组分减少表面处存在的陷阱态和经由场效应组分减少可用于复合过程的电荷载流子的组合效应来实现的。在这里，我们提出了一种技术，场效应钝化硅表面使用的电场效应所提供的碱金属离子存在于覆盖氧化物。这种技术被证明是以可控的方式减少表面复合，并高度稳定。表面复合速度在6-15厘米/秒的范围内被证明为1 Ω cm的n型浮区硅使用这种技术，并观察到它们是恒定的超过300天，而不使用任何额外的表面化学处理。用俘获介导的离子注入模型来描述该体系，并推导出钠和钾碱金属离子物种的去俘获活化能为1.8-2 eV。(C)2014 AIP Publishing LLC.
The recombination of electric charge carriers at the surface of semiconductors is a major limiting factor in the efficiency of optoelectronic devices, in particular, solar cells. The reduction of such recombination, commonly referred to as surface passivation, is achieved by the combined effect of a reduction in the trap states present at the surface via a chemical component, and the reduction in the charge carriers available for a recombination process, via a field effect component. Here, we propose a technique to field effect passivate silicon surfaces using the electric field effect provided by alkali ions present in a capping oxide. This technique is shown to reduce surface recombination in a controlled manner, and to be highly stable. Surface recombination velocities in the range of 6-15 cm/s are demonstrated for 1 Omega cm n-type float zone silicon using this technique, and they are observed to be constant for over 300 days, without the use of any additional surface chemical treatment. A model of trapping-mediated ionic injection is used to describe the system, and activation energies of 1.8-2 eV are deduced for de-trapping of sodium and potassium alkali ionic species. (C) 2014 AIP Publishing LLC.