Engineering of a Near-Infrared Transparent Dielectric–Metal–Dielectric Electrode for <i>p</i> – <i>i</i> – <i>n</i> Perovskite Solar Cells in 4T Silicon/Perovskite Tandem Photovoltaics

The transparent top electrode of perovskite solar cells is crucial for the performance of 4T silicon/perovskite tandem solar cells, but their optimization still faces challenges. For example, employing traditional transparent conductive oxides (TCOs) like indium tin oxide and indium zinc oxide is challenging due to their dependence on scarce indium, energy-intensive deposition methods, and poor mechanical flexibility, which limit their suitability for large-scale, low-cost applications. Here, we developed a DMD electrode based on a low-melting-point dielectric material and a bilayer metal. Our developed single-metal DMD electrode (Cu) shows low transmittance in the near-infrared (NIR) region, and therefore, insertion of very thin Ag improves the average transparency from 53% to 73%. The sheet resistance of the bilayer DMD electrode is ∼15 Ω/sq, which is comparable to that of commercial TCOs; therefore, it was further employed as an electrode for NIR-transparent perovskite solar cells. Our NIR transparent perovskite solar cell devices exhibit a power conversion efficiency of ∼15%, and a power conversion efficiency of >24% is achieved in 4T silicon/perovskite tandem solar cells. Moreover, our approach to utilize an organic dielectric layer and bilayer metal is crucial in developing transparent electrodes for NIR transparent perovskite solar cells and tandem devices.