Application of Hybrid rGO-ITO Bilayer TCO on a-Si Solar Cell for Performance Enhancement

Amine-functionalized reduced graphene oxide (af-rGO) has been synthesized wet-chemically by modified Hummer's method. Raman spectroscopy has been carried out to confirm the presence of the amine group in rGO network. Photoluminescence (PL) spectroscopy has been conducted to reveal the PL conversion property of the af-rGO. Af-rGO colloids with different densities have been coated on a baseline amorphous silicon (a-Si:H) solar cell and the respective optical and solar performances have been compared with the baseline solar cell to optimize the suitable density, which is further validated by investigating the respective field emission scanning electron microscope (FESEM) micrograph of the surface area coverage by rGO on the top of the indium tin oxide (ITO) of the a-Si:H solar cell. The application of af-rGO on the baseline solar cell of the area of 1 cm
²
demonstrated an enhancement in efficiency and short-circuit current density (JSC) of ~1% and ~2 mA/cm
²
, respectively. External quantum efficiency (EQE) measurement reveals that the reductions in sheet resistance and PL converted photons have contributed additional current toward enhanced efficiency for the af-rGO-coated a-Si:H solar cell along with reflectance benefits.