Crystalline silicon solar cells have attracted great attention for their various advantages, such as the availability of raw materials, high-efficiency potential, and well-established processing sequence. Tunnel oxide passivated contact (TOPCon) solar cells are widely regarded as one of the most prospective candidates for the next generation of high-performance solar cells because an efficiency of 26% has been achieved in small-area solar cells. Compared to n-type TOPCon solar cells, the photo conversion efficiency (PCE) of p-type TOPCon is slightly higher. The highest PCEs of p-type TOPCon and n-type TOPCon solar cells are 26.0% and 25.8%, respectively. Despite the highest efficiency in small-area cells, limited progress has been achieved in p-type TOPCon solar cells for large are due to their lower carrier lifetime and inferior surface passivation with the boron-doped c-Si wafer. Nevertheless, it is of great importance to promoting the p-type TOPCon technology due to its lower price and well-established manufacturing procedures with slight modifications in the PERC solar cells production lines. The progress in different approaches to increase the efficiencies of p-type TOPCon solar cells has been reported in this review article and is expected to set valuable strategies to promote the passivation technology of p-type TOPCon, which could further increase the efficiency of TOPCon solar cells.
This study investigated the various physical and electrical effects of silicon direct bonding. Direct bonding means the joining of two wafers together without an intermediate layer. If the surfaces are flat, and made clean and smooth using HF treatment to remove the native oxide layer, they can stick together when brought into contact and form a weak bond depending on the physical forces at room temperature. An IR camera and acoustic systems were used to analyze the voids and bonding conditions in an interface layer during bonding experiments. The I-V and C-V characteristics are also reported herein. The capacitance values for a range of frequencies were measured using a LCR meter. Direct wafer bonding of silicon is a simple method to fuse two wafers together; however, it is difficult to achieve perfect bonding of the two wafers. The direct bonding technology can be used for MEMS and other applications in three-dimensional integrated circuits and special devices.
Wire electrical discharge machining (WEDM) process was evaluated to slice Silicon (Si) for various applications. Specifically, various Si workpieces with various resistances, such as single and multi crystalline Si bricks and wafers were used. As conventional slicing processes, such as slurry-on or diamond-on wire slicing, are based on mechanical abrasions between Si and abrasive, there is a limitation to decrease the wafer thickness as well as kerf-loss. Especially, when the wafer thickness is less than 150 μm, wafer breakage increases dramatically during the slicing process. Single crystalline P-type Si bricks and wafers were successively sliced with considerable slicing speed regardless of its growth direction. Also, typical defects, such as microcracks, craters, microholes, and debris, were introduced when Si was sliced by electrical discharge. Also, it was found that defect type is also dependent on resistance of Si. Consequently, this study confirmed the feasibility of slicing single crystalline Si by WEDM.
The high cost of crystalline silicon solar cells has been considered as one of the major obstacles to their terrestrial applications. Spin on doping (SOD) is presented as a useful process for the manufacturing of low cost solar cells. Phosphorus (P509) was used as an n-type emitters of solar cells. N-type emitters were formed on p-type EFG ribbon Si wafers by using a SOD at different spin speed (1,000∼4,000 rpm), diffusion temperatures (800℃∼950℃), and diffusion time (5∼30 min) in N2+O2 atmosphere. With optimum condition, we were able to achieve cell efficiency of 14.1%.
Citations
Citations to this article as recorded by
SiC Contaminations in Polycrystalline-Silicon Wafer Directly Grown from Si Melt for Photovoltaic Applications Ye-Neung Lee, Bo-Yun Jang, Jin-Seok Lee, Joon-Soo Kim, Young-Soo Ahn, Woo-Young Yoon Journal of the Korea Foundry Society.2013; 33(2): 69. CrossRef
Effects of CMP Retaining Ring Material on the Performance of Wafer Polishing Ki-Won Park, Eun-young Kim, Dong-Sam Park Journal of the Korean Society of Manufacturing Process Engineers.2020; 19(3): 22. CrossRef
Effects of Insert Materials of Retaining Ring on Polishing Finish in Oxide CMP Ki-Won Park, Dong-Sam Park Journal of the Korean Society of Manufacturing Process Engineers.2019; 18(8): 44. CrossRef
Finite Element Analysis on Dynamic Viscoelasticity of CMP Polishing Pad Byeongjun Pak, Dasol Lee, Seonho Jeong, Hyunjin Kim, Haedo Jeong Journal of the Korean Society for Precision Engineering.2019; 36(2): 177. CrossRef
Probe card-Type multizone electrostatic chuck inspection system Yoon Sung Koo, Jae Hwan Kim, Chan Su Han, Sang Jeen Hong Automatika.2023; 64(2): 389. CrossRef
Optimization of Thermal Deformation in Probe Card Yong-Hoon Chang, Jeong-Je Yin, Yong-S. Suh Journal of the Korea Academia-Industrial cooperation Society.2010; 11(11): 4121. CrossRef
First
Prev
