Design and on-chip measurement of CMOS infrared frequency-selective-surface absorbers for thermoelectric energy harvesting

A high-efficiency stacked-film infrared absorber comprising a Jerusalem-cross slot frequency-selective surface (FSS) and Si-based dielectric layers fabricated in foundry CMOS process is proposed. Simulation shows that integration of proposed FSSs with dielectric layers can improve the absorption of the dielectric layers in infrared. A temperature sensing circuit is integrated in CMOS chip to measure the absorption behaviors. The measurement results at 28.3 THz show good trends with simulation. The chip temperature of the FSS-integrated absorber is 7.3% higher than dielectric stacks. The design can be applied for absorbers of CMOS thermoelectric energy harvesters without extra cost.