Amidino-based ligand enables oriented crystallization and boosted carrier extraction for inverted perovskite solar cells and modules

Abstract

High-quality perovskite films with vertical orientation and compact bottom interface are critical for the design and engineering of efficient and stable Cs_xFA_1−xPbI₃-based perovskite solar cells (PSCs). Herein, a robust amidino-based ligand, namely morpholine-4-carboximidamide hydrochloride (M4CH), is introduced into the perovskite precursor to fabricate (001)-dominated perovskite films and simultaneously regulate buried interfacial morphologies and energetics. M4CH enables vertically oriented growth via its strongest adsorption energy on perovskite (001) facets. Concurrently, M4CH accumulates at the buried interface, forming a positive dipole layer to enhance carrier extraction. The resulting inverted methylammonium (MA)-free PSC achieves a champion power conversion efficiency (PCE) of 24.52%, an exceptionally high open-circuit voltage (V_OC) of 1.181 V, and outstanding thermal and environmental stability. Encouragingly, the M4CH-incorporated module, with an aperture of 642 cm², demonstrates an impressive efficiency of 18.54% (certified 18.48%), positioning it among the highest efficiencies recorded for large-scale inverted perovskite solar modules (PSMs).