Fig. 4: Thermal properties of the PSC and the heat dissipation property of F-CEs.

a Schematic diagram of the sun illumination and heat dissipation pathways of the cell. b Absorption of the AM 1.5 G solar irradiance spectrum by different parts of the cell, estimated from cell external quantum efficiency and reflection/transmission spectra. c Schematic diagram of the triple-layer F-CE comprising of a macroporous carbon layer, a graphite layer and a dense carbon layer. (Note: the dense carbon layer mainly acts as a heat-dissipation layer, not conductive layer, which could be replaced by other high emissivity materials, but carbon materials are the first choice.). d Simulated cell temperature under heating power of 780 W m-2. e IR camera measured temperature of varied electrodes having surface temperature of about 90 °C. f Emissivity and conductance of F-CEs and Au electrode.