【公開日：2025.06.10】【最終更新日：2025.05.19】
課題データ / Project Data
課題番号 / Project Issue Number
24JI0049
利用課題名 / Title
Effect of the interlayer on the properties of silicon heterojunction (SHJ) solar cells
利用した実施機関 / Support Institute
北陸先端科学技術大学院大学 / JAIST
機関外・機関内の利用 / External or Internal Use
外部利用/External Use
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）物質・材料合成プロセス/Molecule & Material Synthesis（副 / Sub）計測・分析/Advanced Characterization
【重要技術領域 / Important Technology Area】（主 / Main）マテリアルの高度循環のための技術/Advanced materials recycling technologies（副 / Sub）-
キーワード / Keywords
高度素材識別技術/ Advanced material identification technology,集束イオンビーム/ Focused ion beam
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
Chen Wen Jauh
所属名 / Affiliation
Graduate School of Materials Science, National Yunlin University of Science and Technology, Taiwan
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
Higashimine Koich
利用形態 / Support Type
（主 / Main）技術代行/Technology Substitution（副 / Sub）,機器利用/Equipment Utilization
利用した主な設備 / Equipment Used in This Project
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
In silicon heterojunction (SHJ) solar cells, the hydrogenated amorphous silicon (a-Si: H) thin layer is too low in transverse conductivity to effectively collect charge carriers horizontally over the metal electrodes. Additional transparent conductive oxide layers, such as Sn-doped In2O3 (ITO), are deposited at the top. In addition to charge collection, another essential function of the frontend transparent conductive oxide (TCO) layer is to act as an anti-reflective layer. The electroplating technology can effectively reduce the cost of electrodes. The Cu metallization process introduces SHJ solar cells, which is crucial to improving the SHJ solar cell industry's competitiveness. However, copper has a high diffusion coefficient and high solubility in silicon and the formation of copper silicide at low temperatures. In silicon solar cells, nickel is typically used as a copper diffusion barrier. The interlayers and/or interfaces may affect the properties of the silicon heterojunction (SHJ) solar cells. The study will investigate the effect of the interlayer on the properties of silicon heterojunction (SHJ) solar cells.
実験 / Experimental
This study used commercially available single crystal (0 0 1) oriented silicon wafers with a textured roughness of around 3-5 μm as substrates. A process involving acetone and an H2SO4/H2O2 solution was used to clean the textured silicon substrates. The substrates were then dipped into a hydrogen fluoride solution before being loaded into the sputtering chamber. A direct current (dc) magnetron sputtering system was used to deposit Al, Ni and Cu films onto the textured silicon substrates. The sputtering occurred at room temperature (25 °C), and the base pressure of the vacuum chamber was 4 x 10-6 Torr. The structure of the samples was analyzed using scanning transmission electron microscopy. TEM was performed on a JEM-ARM200.
結果と考察 / Results and Discussion
In SHJ technology, the metallic contacts are generally deposited on a transparent conductive oxide (TCO). Contact metallization on TCOs is typically performed by screen-printing of low-temperature Ag-pastes. Electroplating of copper is becoming more attractive to reduce precious Ag consumption. However, copper may come into direct contact with the silicon. Therefore, the seed layers are typically applied using physical vapor deposition (PVD) or sputtering techniques. The purpose of the metal seed layer is to prevent interdiffusion between copper and silicon. In this report, Ni/Al is used as the interlayer between the copper and silicon. Typical scanning transmission electron microscope (STEM) cross-section views of Ni/Al/Si are shown in Figs. 1 and 2. The low and high-magnification STEM micrographs of the Ni/Al/Si sample are shown in Figures 1 and 2, respectively. The line scan across the Ni/Al/Si using STEM-EDS is shown in Figure 3. The distribution of Al in the Ni/Al/Si stack is located at a scale between 50 and 90 nm, which reveals that the thickness of the Al layer is approximately 40 nm. The thickness of the Ni layer is nearly 50 nm. The EDS maps of Si, Ni, and A are also performed. The elemental maps reveal the stable Ni/Al/Si stack structure. An amorphous interlayer is present at the Al and silicon interface.
図・表・数式 / Figures, Tables and Equations
Figure 1: The low-magnification STEM micrographs of the Ni/Al/Si sample
Figure 2: The high-magnification STEM micrographs of the Ni/Al/Si sample
Figure 3: The line scan across the Ni/Al/Si using STEM-EDS
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
No
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
- No
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件