Solar Energy, Vol.217, 390-398, 2021
Enhancement in the multi-junction thermophotovoltaic system based on near-field heat transfer and hyperbolic metamaterial
A multi-junction thermophotovoltaic system based on near-field radiation and hyperbolic metamaterial was developed. The multilayer near-field system is studied through the fluctuational electrodynamics based on dyadic Green's function and a recursive calculation model, whereas the external quantum efficiency, open-circuit voltage and fill factor are considered to evaluate the performance of the photovoltaic cell. The system expands the available spectrum to 1720-3650 nm so that more photons can be recovered. The near-field radiative transfer is further improved owing to the infinite wavevector in the hyperbolic metamaterial. The results demonstrate that the multi-junction system generates 4.7236 x 10(6) W/m(2) of electricity with a conversion efficiency of 45.26%, achieving 1.3 times (2.38 times) more electricity with 15.3% (25.95%) higher conversion efficiency than the single InGaAsSb (InAs) cell. The study further improves the performance of the multi-junction thermophotovoltaic and paves the way to design a more efficient near-field multi-junction thermophotovoltaic system.