Advanced passivation techniques for Si solar cells with high-kappa dielectric materials

作者：Geng, Huijuan; Lin, Tingjui; Letha, Ayra Jagadhamma; Hwang, Huey-Liang^*; Kyznetsov, Fedor A.; Smirnova, Tamara P.; Saraev, Andrey A.; Kaichev, Vasily V.

来源：Applied Physics Letters, 2014, 105(12): 123905.

DOI：10.1063/1.4896619

• SURFACE RECOMBINATION
• SILICON
• CHEMISTRY
• FILMS

Electronic recombination losses at the wafer surface significantly reduce the efficiency of Si solar cells. Surface passivation using a suitable thin dielectric layer can minimize the recombination losses. Herein, advanced passivation using simple materials (Al2O3, HfO2) and their compounds H((Hf))A((Al))O deposited by atomic layer deposition (ALD) was investigated. The chemical composition of Hf and Al oxide films were determined by X-ray photoelectron spectroscopy (XPS). The XPS depth profiles exhibit continuous uniform dense layers. The ALD-Al2O3 film has been found to provide negative fixed charge (-6.4 X 10(11) cm(-2)), whereas HfO2 film provides positive fixed charge (3.2 X 10(12) cm(-2)). The effective lifetimes can be improved after oxygen gas annealing for 1min. I-V characteristics of Si solar cells with high-kappa dielectric materials as passivation layers indicate that the performance is significantly improved, and ALD-HfO2 film would provide better passivation properties than that of the ALD-Al2O3 film in this research work.

• 出版日期2014-9-22
• 单位上海交通大学; 中国科学院电工研究所; 清华大学