Impact of metal-organic vapor phase epitaxy environment on silicon bulk lifetime for III–V-on-Si multijunction solar cells
Impact of metal-organic vapor phase epitaxy environment on silicon bulk lifetime for III–V-on-Si multijunction solar cells
复制标题
金属有机气相外延环境对 III-V-on-Si 多结太阳能电池硅体寿命的影响
DOI：
10.1016/j.solmat.2014.01.034
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发表时间：
2014
影响因子：
6.9
通讯作者：
I. Rey‐Stolle
中科院分区：
文献类型：
--
作者：
E. García;I. Rey‐Stolle
以在串联太阳电池硅衬底上集成III-V材料为最终目标，研究了金属-有机气相外延(MOVPE)环境对硅片少数载流子特性的影响。这些特性将从根本上决定III-V-on-Si串联太阳能电池底部电池的光伏性能。比较了在MOVPE反应器中对直拉硅片进行不同热处理所获得的基区少数载流子寿命。在表面制备过程中，观察到少数载流子寿命的显著下降(即氢退火)。人们提出了三种不同的机制来解释这种行为：(1)来自反应堆的外在杂质的引入；(2)来自晶片本身的本征寿命杀死杂质的激活；以及(3)晶体缺陷的形成，最终成为复合中心。此外，还对磷扩散形成发射体的效果进行了评价。在这个意义上，已经报道了在发射极形成过程中，通过P对提取杂质的作用或通过原子氢对缺陷的钝化作用，可以恢复发射极的寿命。
With the final goal of integrating III–V materials on silicon substrates for tandem solar cells, the influence of the metal-organic vapor phase epitaxy (MOVPE) environment on the minority carrier properties of silicon wafers has been evaluated. These properties will essentially determine the photovoltaic performance of the bottom cell in a III–V-on-Si tandem solar cell. A comparison of the base minority carrier lifetimes obtained for different thermal processes carried out in a MOVPE reactor on Czochralski silicon wafers has been carried out. An important degradation of minority carrier lifetime during the surface preparation (i.e. H2anneal) has been observed. Three different mechanisms have been proposed for explaining this behavior: (1) the introduction of extrinsic impurities coming from the reactor; (2) the activation of intrinsic lifetime killing impurities coming from the wafer itself; and finally, (3) the formation of crystal defects, which eventually become recombination centers. The effect of the emitter formation by phosphorus diffusion has also been evaluated. In this sense, it has been reported that lifetime can be recovered during the emitter formation either by the effect of the P on extracting impurities, or by the role of the atomic hydrogen on passivating the defects.