Fully Printed High‐Performance Quasi‐Two‐Dimensional Perovskite Solar Cells via Multifunctional Interfacial Engineering

Abstract Planar n–i–p carbon perovskite solar cells (PSCs) with a hole transport layer that can be fabricated at low temperatures at low‐cost exhibit great potential for large‐scale manufacturing. Moreover, 2D perovskites have attracted considerable attention owing to their higher stability. In this work, scalable and highly efficient fully printed large‐area carbon electrode‐based 2D perovskite modules are reported through the insertion of a thin naphthaleneimide derivative (CATNI)‐based interfacial layer between tin (IV) oxide and the perovskite layer. The results show that this facilitates the formation of the interfacial contact, suppresses energy losses, and substantially improves the performance parameters of the PSCs, especially their V OC value. A significantly enhanced V OC of 1.13 V is achieved resulting in the device PCE value reaching over 18%, which is one of the highest reported for fully printed PSCs so far. It is found that with the deployment of this CATNI‐based interfacial layer, a more efficient carrier extraction is achieved. This ultimately contributed to enhanced spectral response as well as improved V OC for these carbon electrodes based on fully printed devices. Finally, the carbon‐perovskite solar modules (carbon‐PSMs) are fabricated on ITO glass substrates with dimensions of 5.0 × 5.0 cm. These prepared modules exhibited outstanding photovoltaic performance with the highest PCE value of over 14.6%.