Graphene as a transparent conducting and surface field layer in planar Si solar cells
1 Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
2 Semiconductor Devices and Photovoltaics Department, Electronics Division, Bharat Heavy Electricals Limited, Mysore Road, Bangalore 560026, India
Nanoscale Research Letters 2014, 9:349 doi:10.1186/1556-276X-9-349Published: 13 July 2014
This work presents an experimental and finite difference time domain (FDTD) simulation-based study on the application of graphene as a transparent conducting layer on a planar and untextured crystalline p-n silicon solar cell. A high-quality monolayer graphene with 97% transparency and 350 Ω/□ sheet resistance grown by atmospheric pressure chemical vapor deposition method was transferred onto planar Si cells. An increase in efficiency from 5.38% to 7.85% was observed upon deposition of graphene onto Si cells, which further increases to 8.94% upon SiO2 deposition onto the graphene/Si structure. A large increase in photon conversion efficiency as a result of graphene deposition shows that the electronic interaction and the presence of an electric field at the graphene/Si interface together play an important role in this improvement and additionally lead to a reduction in series resistance due to the conducting nature of graphene.