Multiscale investigation of the plasmonic solar cell in the spectral splitting concentrating photovoltaic-thermal system

Abstract Concentrating photovoltaic-thermal systems are appealing methods for use in broadband solar applications. A spectral splitting concentrating photovoltaic-thermal system with the plasmonic solar cell is proposed to predict the system-dependent performance from solar irradiation to electrical output. The multiscale model is built by considering geometric ray-trace optics, plasmonic enhanced light absorption, and charge carrier transport. The ray-trace process is evaluated using the Monte-Carlo method, while the plasmonic absorption is analysed with the finite-difference time-domain method. The local concentration ratio is obtained to provide concentrated irradiation for the plasmonic solar cell, where a coupled optical-thermal-electrical simulation is conducted considering the physics of the semiconductor. The geometric parameters of the system are optimized with a homogeneous solar flux, high concentration ratio, and large available area for the plasmonic solar cell. The homogeneous solar flux has a maximum electrical efficiency of 21.97% when the relative focal length of the spectral splitting filter is 0.04, and a maximum fill factor of 0.88 is obtained when the relative focal length of the spectral splitting filter is 0.03. The dominant energy loss of the proposed system is found to be material loss. The spectral splitting filter can facilitate broadband solar utilization, but concentrating irradiation will aggravate the thermalization loss. This work provides design guidance for concentrating systems with nanostructured solar cells.