Plasmonic Metamaterial’s Light Trapping Enhancement of Ultrathin PbS-CQD Solar Thermal PV Cells

Enhancing photon absorptance in ultrathin solar/thermophotovoltaic (STPV) cells is crucial for low-cost highly efficient cells. A complete study of power conversion enhancement, in a proposed ultrathin STPV cell, is presented here. It involves lead sulfide colloidal quantum dots (PbS-CQDs), a silver (Ag)-nano-pyramid design, aluminum nitride (AlN) crossed prisms as front texturization, with embedded Ag nanospheres, and a tantalum (Ta) film as a back reflector. By combining the three mechanisms of surface plasmon polariton (SPP), localized plasmons (LSPR), and magnetic polariton (MP) in the same structure, photon absorptance in the active PbS-CQDs layer is greatly improved. The suggested structure attained a highly active absorptance of over 80%, covering visible and near-infrared (0.30–1.77 µm). The short circuit current density is also evaluated under AM 1.5 solar illumination and various blackbody temperatures (T_B), with values of 48.90 mA cm⁻² and 6.93 mA cm⁻², respectively, corresponding to unprecedented power conversion efficiencies (PCEs) of 20.20% and 15.58%. The effects of metamaterial light management on PCE enhancement are discussed. Collectively, the findings show that the proposed hybrid cell is potentially useful in high-performance hybrid thermal and solar cells.