Jia Xiaojie, Zhou Chunlan, Wang Wenjing
The Key Laboratory of Solar Thermal Energy and Photovoltaic System, Institute of Electrical Engineering, Chinese Academy of Science (CAS), Beijing, China.
University of Chinese Academy of Sciences (UCAS), Beijing, China.
Nanoscale Res Lett. 2017 Dec;12(1):193. doi: 10.1186/s11671-017-1910-6. Epub 2017 Mar 16.
Black silicon shows excellent anti-reflection and thus is extremely useful for photovoltaic applications. However, its high surface recombination velocity limits the efficiency of solar cells. In this paper, the effective minority carrier lifetime of black silicon is improved by optimizing metal-catalyzed chemical etching (MCCE) method, using an AlO thin film deposited by atomic layer deposition (ALD) as a passivation layer. Using the spray method to eliminate the impact on the rear side, single-side black silicon was obtained on n-type solar grade silicon wafers. Post-etch treatment with NHOH/HO/HO mixed solution not only smoothes the surface but also increases the effective minority lifetime from 161 μs of as-prepared wafer to 333 μs after cleaning. Moreover, adding illumination during the etching process results in an improvement in both the numerical value and the uniformity of the effective minority carrier lifetime.
黑硅具有出色的抗反射性能，因此在光伏应用中极为有用。然而，其较高的表面复合速度限制了太阳能电池的效率。在本文中，通过优化金属催化化学蚀刻（MCCE）方法来提高黑硅的有效少数载流子寿命，该方法使用原子层沉积（ALD）沉积的AlO薄膜作为钝化层。采用喷涂法消除对背面的影响，在n型太阳能级硅片上获得了单面黑硅。用NHOH/HO/HO混合溶液进行蚀刻后处理，不仅使表面光滑，还将有效少数载流子寿命从制备好的晶片的161微秒提高到清洗后的333微秒。此外，在蚀刻过程中增加光照可提高有效少数载流子寿命的数值和均匀性。
