Role of Hole-Selective Contact in Efficiency Improvement of ITO-Free InP/MoO3/ PEDOT:PSS Nanowire Solar Cells

The use of nanostructures over traditional bulk and thin-film solar cells (SCs) increases the efficiency per unit volume due to the coupled effects of intrinsic antireflection and strong excitation of resonance modes. The structural optimization of InP nanowires (NWs) provides a deep insight into the electrical and optical parameters of NWs influenced by structural morphology. Here, we propose a core–shell structure using n-InP NW as a core coated with PEDOT:PSS/MoO ₃ shell. We simulated the resultant structure using the finite difference time domain (FDTD) and device modules of Lumerical to investigate its optical and electrical behavior. The optical simulation predicts that a hole-selective layer over InP core increases the absorption of incident photons. An optimized thickness of shell reduces the required core material without affecting the ideal current density, resulting in low manufacturing cost. For core doping of $5\times10$ ¹⁸ cm ⁻³ , surface recombination velocity (SRV) of 10 ⁴ cm/s, and minority carrier lifetime ( $\tau_{p}$ ) of 40 ns, an efficiency of ~25% can be achieved. In this article, we have also compared the optical and electrical characteristics of uncoated, PEDOT:PSS/InP NW and ITO/InP NW and electron-selective oxide-coated InP NW with our proposed structure and found that our proposed structure PEDOT:PSS/p-MoO ₃ / n-InP heterojunction NWSC exhibits better photovoltaic (PV) performance than the above-mentioned structures.