Evidence of solute PEDOT:PSS as an efficient passivation material for fabrication of hybrid c-Si solar cells

Abstract

A new aspect of solute PEDOT:PSS was explored, its function as an excellent passivation material. Solute PEDOT:PSS with a thickness of 9.4 nm exhibited an effective carrier lifetime of 940 μs at an injection level of 1 × 10¹⁴ cm⁻³. A new architecture of hybrid crystalline silicon solar cells with highly conductive PEDOT:PSS on the front side and solute PEDOT:PSS on the backside was demonstrated. The reverse saturation current density J_o of 9.4 nm-thick solute PEDOT:PSS was evaluated as 2.2 × 10⁻¹⁴ A cm⁻², which is ten times lower than that without solute PEDOT:PSS on the backside, 1.45 × 10⁻¹³ A cm⁻². With the introduction of 7.5 nm-thick solute PEDOT:PSS on the backside, the performance drastically improved with an open-circuit voltage V_OC of 618 mV, short-circuit current density J_SC of 28.33 mA cm⁻² and power conversion efficiency E_ff of 11.45% owing to efficient passivation. Employment of solute PEDOT:PSS as an efficient passivation material opens a new route for the fabrication of hybrid c-Si solar cells, which is facile, reproducible and environmentally friendly.