Toward Energy Generation Enhancement in InP Nanorods Embedded Solar Cells Exploiting the Localized Mie Resonance

Abstract A p-n junction-based solar cell, comprising four layers of TiO₂, InP nanorods, Si, and Ag, was investigated to study the impact of InP nanorods on Mie resonance, carrier generation rate, photon current, and overall performance in the ultraviolet (UV) and visible bands. Initially, TiO₂ layer of varying thickness was used as anti-reflector and absorber without InP nanorods to determine the optimal thickness to maximize carrier generation, while keeping the Si layer thickness fixed. The bottom Ag layer acts as a back reflector and a metallic contact. The results revealed the use of a 200 nm thick TiO₂ layer maximized career generation and short-circuit current. 3.2 eV bandgap of the TiO₂ layer enhances UV light absorption and serves as a protective layer for the Si layer (which has weak performance in the UV band due to surface recombination). Next, the InP nanorods were formed at the interface of TiO₂ and Si layers. These nanorods were optimized for key operations, such as light scattering, recombination, surface area enhancement, and quantum effects. Herein, the Mie resonance was studied in larger InP nanorods and the impact of weak Mie resonance on the quantum effect due to the smaller ones. The solar cell model includes a silver base and silver emitter to extract the I-V characteristics. The maximum efficiency of ∼6.51% was achieved using the InP nanorods of 5 nm radius and 20 nm thickness – the case which significantly enhances the quantum confinement effect and improves the bandgap, allowing for extended light harvesting in the UV and visible regime.