Graphene constructed carbon thin films as transparent electrodes for solar cell applications

Abstract

Here, we report fabrication of transparent graphene constructed carbon films (TGFs), from the botanical derivative camphor by controlled pyrolysis, for solar cell applications. TGFs show very good transparency in a wide range of wavelengths (0.3–2 μm) in contrast to indium tin oxide, which shows strong absorptions in the near infrared region. Electrical measurement show the high conductivity of the TGFs and their thickness dependent sheet resistance. An organic solar cell was fabricated on a TGF electrode with a transparency of 81% at 550 nm and a conductivity of 357 S cm⁻¹. The dark light characteristic of the device shows very good rectification with minimum current leakage. Under illumination the device showed very good open circuit voltage, while the short circuit current density and fill factor were affected by the high sheet resistance of the TGFs. This finding shows that TGFs could be suitable electrode materials for organic solar cells, as well as for other transparent electronic devices.