Performance analysis of ITO-free PEDOT:PSS/InP nanowire hybrid solar cell

Abstract

InP nanostructure based solar cells (SCs) offer high efficiency with reduced material requirement when compared to their planar/thin-film SCs. In order to further reduce the cost and improve the effectiveness of nanostructured SCs, a new approach by combining the organic and inorganic materials in the active layer has been developed. In this study, we have replaced the indium tin oxide (ITO) with PEDOT:PSS as the transparent conducting oxide since its sheet resistance is virtually comparable to that of ITO and exhibits almost similar performance as an electrode. Geometrical parameters such as diameter (D) of InP nanowire (NW) and coating thickness (T) of PEDOT:PSS are optimized by FDTD technique to achieve best absorption and optical current density (Jsc). It is observed that for PEDOT:PSS/InP NWSCs with 160 nm of InP NW diameter and coating thickness of 80 nm for PEDOT:PSS, optical current density of 34.2 mA/cm2 is achieved, which is better than the ITO/InP NWSCs. Electrical analysis of PEDOT:PSS/p-InP/n-InP NW homojunction SCs using Charge Solver Module revealed that the power conversion efficiency (PCE) of ∼ 24% can be attained with the proposed nanostructures through a carrier lifetime of 1 ns, surface recombination velocity (SRV) of 103 cm/s of InP NW (at n-InP and p-InP interface) and core doping of 5 × 1018 cm−3. We also found out that conformally coated NWs outperform fully infiltrated NW structures in terms of optical and electrical performance.