Graphene-Si solar cells using 2D hBN monolayer passivation

• Main Author: Mohamed Ashraf Bin Mohamed Abubakar
• Other Authors: Kim Munho
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Graphene-Si solar cells using 2D hBN monolayer passivation
• Online Access: https://hdl.handle.net/10356/181686
• Institution: Nanyang Technological University

This project explores the integration of graphene and 2D hexagonal boron nitride (hBN) monolayers in silicon (Si) solar cells to enhance efficiency and stability. Graphene’s high electrical conductivity and transparency, coupled with hBN’s dielectric properties, offer a promising approach to reducing surface recombination losses. The study involves the fabrication of Graphene-Si solar cells with hBN passivation, comparing their performance with other variants, including black graphene, black hBN graphene, and planar graphene. Using chemical vapor deposition (CVD), graphene and hBN layers were deposited on Si substrates, followed by current-voltage (IV) measurements and irradiance testing. Key performance indicators such as open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF), and efficiency (η) were analyzed to evaluate the role of hBN in improving surface passivation and charge carrier mobility. The results show that Graphene-Si solar cells with hBN passivation outperform conventional Si cells and other graphene variants, particularly under varying irradiance levels. hBN effectively reduces surface recombination, enhancing efficiency. While black graphene and black hBN graphene improve light absorption, they do not provide the same level of recombination suppression. Planar graphene cells exhibited limited improvements. In addition, long-term stability tests, including thermal cycling, light exposure, and humidity resistance, revealed that hBN passivation significantly enhances durability, with minimal degradation in Voc and Isc over time. These findings demonstrate the potential of combining graphene with hBN passivation for improved photovoltaic performance and longevity, positioning graphene-based solar cells as a promising solution for next-generation solar technology.