Development of two-step etching approach for aluminium doped zinc oxide using a combination of standard HCl and NH₄Cl etch steps

详细信息	查看全文 | 推荐本文 |

• 作者：S. Ferná ; ndez^a ; ^{susanamaria.fernandez@ciemat.es} ; S.E. Pust^b ; J. Hü ; pkes^b ; F.B. Naranjo^c
• 关键词：ZnO ; Al ; Etching method ; NH4Cl ; Scattering properties ; Silicon thin solar cells
• 刊名：Thin Solid Films
• 出版年：2012
• 期刊代码：78_00406090
• 类别：ph
• 出版时间：1 May, 2012
• 卷：520
• 期：14
• 页码：4678-4684
• 文件大小：1072 K

摘要

An etching method for ZnO:Al films deposited by radio-frequency sputtering is presented. The method is developed to achieve appropriate surface morphology for efficient light scattering. This etching method consists of a first step where the sample is dipped in standard diluted HCl (0.5 wt.%) for 40 s (the 鈥渟tandard J眉lich鈥?etch process) and a subsequent step where a NH₄Cl aqueous solution with concentrations ranging from 2 to 20 wt.%is used. The introduction of the second step leads to a slight modification of the surface feature shape and an increase in the surface roughness of up to around 37%in relation with that obtained using only the first step. High haze values are also obtained, reaching up to 93%at 550 nm and strong light scattering into angles above 50掳 at 632 nm. On the other hand, the resistivity of the textured films remains low enough for cell application, being ranged from 6 to 13 惟/sqr depending on the NH₄Cl concentration used. Finally, in order to assess the role of the features obtained on the surface as effective light trapping, the textured films are applied as front contact in silicon thin film solar cells.