We investigate the effect of current injection during contact formation of an Ag-based screen-printed electrode to boron-doped emitters, which differ by their sheet resistances. The average contact resistivities between the metal electrode and silicon of all the boron-doped emitter samples are ∼3 mω cm2, regardless of the sheet resistance (75-145 Ω/sq), and the lowest values are below 1 mω cm2 using the injection of a current density of 5 A/cm2 during the metallization process. Additionally, the injection of current to a phosphorus-doped emitter in the opposite direction suppressed the formation of the Ag precipitates and crystallites and increased the contact resistivity of over 300 mω cm2, which is comparable to that obtained when Ag paste is applied to a boron-doped emitter with no current injection. This finding indicates that electrons are essential for the reduction of Ag ions during high-temperature metallization process using the screen-printing technique and that the injection of current can control the contact formation and enhance the efficiency of solar cells. Finally, we suggest a suitable process for reducing the contact resistivity in manufacturing n-type Si solar cells.
Bibliographical noteFunding Information:
Manuscript received November 19, 2018; revised January 9, 2019 and January 24, 2019; accepted January 28, 2019. Date of publication February 19, 2019; date of current version April 19, 2019. This work was supported in part by the New & Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning granted financial from the Ministry of Trade, Industry & Energy, Republic of Korea (20163010012430 and 20173010012970), and in part by the Korea University Grant. (Corresponding authors: Yoonmook Kang, Hae-Seok Lee, and Donghwan Kim.) S. Bae, J.-W. Choi, C. Kim, S. H. Shin, and H. Park are with the Department of Materials Science and Engineering, Korea University, Seoul 02841, South Korea (e-mail:, email@example.com; firstname.lastname@example.org; email@example.com; firstname.lastname@example.org; email@example.com).
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- Boron-doped emitter
- crystalline Si solar cells
- current injection
- screen printing
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering