Pyramid‐Textured Antireflective Silicon Surface In Graphene Oxide/Single‐Wall Carbon Nanotube–Silicon Heterojunction Solar Cells

• Published in: Energy & environmental materials (Hoboken, N.J.) Vol. 1; no. 4; pp. 232 - 240
• Main Authors: Yu, LePing, Batmunkh, Munkhbayar, Dadkhah, Mahnaz, Shearer, Cameron J., Shapter, Joseph G.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.12.2018
• Subjects: antireflection treatment; Carbon; Carbon nanotubes; Control equipment; Electromagnetic absorption; Etching; Graphene; Heterojunctions; Photoelectric effect; Photovoltaic cells; Photovoltaics; Pyramids; Reaction time; Reflectance; Silicon; Solar cells
• ISSN: 2575-0356; 2575-0356
• DOI: 10.1002/eem2.12020

Antireflection layers are commonly used in photovoltaics to increase light absorption and therefore increase maximum photocurrent. Here, pyramid structures are created on Si surfaces with alkaline solution etching. The extent of pyramid coverage depends directly on the reaction time and as a result, the surface reflectance decreases with reaction time. A floating transfer method is used to fabricate heterojunction solar cells based on graphene oxide‐carbon nanotube and Si heterojunctions. The best device performance (photo current conversion efficiency of 13.01 ± 0.32%, which is much higher than the efficiency of the control devices (10.18 ± 0.33%)) was observed using with cells fabricated with the highest coverage (99.9%) of pyramids on the Si surfaces, which is determined to be a combined effect of reduced surface reflectance and increased effective heterojunction area per unit active area. Adding a pyramidal structure to the Si under the carbon nanotube (CNT) layer in a CNT‐Si solar cell has been shown to dramatically improve the device performance. This work also explores in detail the conformational deposition of the film and its consequence to performance.