Solid‐State Monolithic Dye‐Sensitized Solar Cell Exceeding 10% Efficiency Using a Copper‐Complex Hole Transport Material and a Carbon Counter‐Electrode

Abstract

The continuous growth of the Internet of Things devices operating indoor triggers the development of indoor photovoltaic (iPV) technologies to power them. Dye‐sensitized solar cells (DSSCs) with Cu‐based complexes as hole transport material (HTM) and organic sensitizers are among the most efficient, safe, and sustainable options for iPVs. The typical copper‐mediated DSSCs are assembled in the conventional configuration using PEDOT:PSS counter‐electrodes. Herein, a highly efficient solid‐state monolithic DSSCs with a copper‐complex HTM and a carbon counter‐electrode are developed. The monolithic structure allows a low‐cost and direct design for producing in‐series modules, which is very attractive for the market‐scale production of iPVs. Typical devices display average power conversion efficiencies (PCEs) of ≈9.5%–10% under 1‐sun simulated solar light provided by a Class ABA light‐emitting diode Solar Simulator. The best energy performing device renders a stable PCE of 10.4% under 1‐sun and PCEs of 26.1% and 28.5% under 600 lx and 1000 lx indoor light, respectively. The performance of a typical device is independently confirmed at Fraunhofer Institute for Solar Energy Research, with a certified PCE of 8.7% using a Class AAA Xenon Solar Simulator (AM1.5 G, 25 °C).