High-performance, large-area semitransparent and tandem perovskite solar cells featuring highly scalable a-ITO/Ag mesh 3D top electrodes

The photovoltaic performance and scalability potential of a semitransparent perovskite solar cells (ST-PSCs) are primarily determined by the optoelectronic properties of the top transparent conducting electrode (TCE) used. Herein, we demonstrate the scalable fabrication of ST-PSC using a three-dimensional (3D) TCE consisting of (i) a sputtered amorphous indium-tin-oxide (a-ITO) film and (ii) silver (Ag) mesh subelectrodes prepared via a 3D direct-ink writing technique. At an optimized aspect ratio of 0.5, the a-ITO/Ag mesh 3D TCE exhibits a sheet resistance of < 1 Ω/□ and a transparency of ~85%. Utilizing the a-ITO/Ag mesh as a top contact, standard (0.07 cm²) and large-area (1.0 cm²) ST-PSCs achieved power conversion efficiencies (PCE) of 16.26% and 15.52%, respectively, with > 85% transmittance in the near-infrared region. Moreover, the ST-PSCs displayed superior ambient and thermal stability than the opaque PSCs due to the presence of a-ITO buffer that prevents moisture ingress and ions migration. Using ST-PSC as a top cell, the standard (0.07 cm²) and large-area (1.0 cm²) four-terminal ST-PSC/SiSC tandem cells achieved PCEs of 26.47% and 24.70%, respectively. To the best of our knowledge, our tandem cell showed the minimum efficiency roll-off among all the reported large-area tandem cells, manifesting the scalability potential of our ST-PSCs.