Analysis of Optical Potential and Electrical Loss between Upright Pyramids and Inverted Pyramids on Silicon Heterojunction Solar Cells

Several studies have demonstrated that inverted pyramid (IP) structures confer significant advantages over upright pyramid (UP) designs in silicon solar cells. Nevertheless, the most notable efficiency records of the past decades have been predominantly set using UP configurations, rather than IP structures. Herein, both UP and IP structures are fabricated to assess their performance on wafer and silicon heterojunction (SHJ) solar cells. The optical benefits of IP structures on wafers are drastically curtailed when applied on SHJ solar cells due to the introduction of front antireflective films, as also verified through optical simulations. Additionally, the IP textured device exhibits a 3.35% efficiency difference compared to the UP textured one, attributed to enhanced surface recombination, higher series resistance, and lower shunt resistance. Furthermore, optical simulations suggest that substrate thickness hardly impacts the preference for UP or IP structures after normalizing the sizes and tilt angles, while the incident angle and rear reflective layer are critical factors. Quokka 2 and Wafer Ray Tracer are used for optical and electrical simulations, respectively.