High-Efficiency Solar Energy Conversion Based on Quantum Optics: Theory and Experimental Study

Based on the principles of quantum optics, this work systematically conducts theoretical analysis, simulation, and experimental study on high-efficiency solar energy conversion. By establishing a microscopic dynamic model of quantum dot thin-film solar devices, the theoretical basis for performance enhancement through multiple exciton generation (MEG) and energy up-conversion is derived. Using the finite-difference time-domain (FDTD) method and many-body dynamic simulations, the effects of different quantum dot sizes and film thicknesses on light absorption, external quantum efficiency (EQE), short-circuit current density (Jsc), and open-circuit voltage (Voc) were investigated. Simulation results show that when the quantum dot radius is 4 nm and the film thickness is 100 nm, the absorption efficiency reaches as high as 92%, with a maximum EQE of 96%. The short-circuit current density (Jsc) reaches 41.5 mA/cm², the open-circuit voltage (Voc) is 0.69 V, and the theoretical power conversion efficiency (PCE) achieves 23.5%. Experimental tests are consistent with simulation trends, showing an average absorption efficiency of 91% in the 400–800 nm range, a peak EQE of 94%, a Jsc of 40.8 mA/cm², a Voc of 0.68 V, and a PCE improved to 22.8%. Compared with traditional silicon-based devices, quantum dot thin-film devices demonstrate significant improvements in spectral response and energy conversion performance.