Jpn. J. Appl. Phys. 51 (2012) 04DP07 (4 pages)  |Previous Article| |Next Article|  |Table of Contents|
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Optimization of Amorphous Si/Crystalline Si Heterojunction Solar Cells by BF₂ Ion Implantation

Tzong-Han Tsai, Yung-Chun Wu, Shih-Sian Yang, and Chun-Hao Chen

(Received September 26, 2011; accepted December 12, 2011; published online April 20, 2012)

In this study we evaluated two approaches to improving the efficiency of amorphous Si/crystalline Si (a-Si/c-Si) heterojunction solar cells by BF₂ ion implantation. First, emitter layer formation was compared for the cases of B and BF₂ ion implantation when using the same 7° tilt angle. Second, emitter layer formation was compared between a 7° tilt angle and a 60° tilt angle when using BF₂ ion implantation. The experimental results reveal that the fluorine in BF₂ passivates the defects at the a-Si and a-Si/c-Si interface, and ion implantation at a high 60° tilt angle forms a shallow solar cell junction. The emitter layer formed by BF₂ ion implantation with a 60° tilt angle in an a-Si/c-Si heterojunction solar cell achieves the highest short circuit current density (J_SC) of 36.85 mA/cm² with a conversion efficiency (η) of 14.41%.

URL: http://jjap.jsap.jp/link?JJAP/51/04DP07/
DOI: 10.1143/JJAP.51.04DP07

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