Coordinating light management and advance metal nitride interlayer enables MAPbI3 solar cells with >21.8% efficiency

Abstract

Due to the continuous increase in power conversion efficiencies (PCEs), perovskite solar cells (PSCs) are widely considered as the most promising technology for third generation photovoltaics. Improving optical absorption while reducing electrical losses is still a challenge towards attaining PCE values closer to the Shockley-Queisser limit. However, frequently used strategies to improve light absorption (e.g. via texturing the front surface) often cause electrical recombination losses. Here, we successfully relaxed the competing mechanisms between electrical and optical properties by integrating a modulated textured substrate and an amorphous metal nitride interface modification layer to combine enhanced light scattering and reducing interfacial recombination losses in PSCs. This comprehensive electro-optical management presents several advantages, including increased light absorption, promoting bandgap alignment and passivating the underlying perovskite defects. Consequently, the resulting MAPbI3 solar cells exhibit a high open-circuit voltage of 1.17 V and the concomitant high PCE of 21.84%. In addition, we also use numerical simulations to propose approaches towards achieving high efficiency (PCE>30%) PSCs. Besides expanding the pool of available strategies for improving the efficiency of PSCs, from photon management to interface engineering, our work also offers a systematic guidance for the design and fabrication of high performance photovoltaic devices.