An Approach to Quantify the Negative Capacitance Features in a Triple‐Cation based Perovskite Solar Cells
Hassen Dhifaoui, Naveen Harindu Hemasiri, Walid Aloui, Abdelaziz Bouazizi, Samrana Kazim, Shahzada Ahmad
Abstract
Abstract Understanding the device kinetics occurring in the bulk and at the charge selective interfaces is vital for optimizing the performance of perovskite solar cells (PSCs) and their development. Planar PSCs are studied with and without hole transport layer (HTL) and power conversion efficiency of 16.23% is measured with poly(3‐hexylthiophene) [P3HT] as HTL, while the PSCs without HTL show significant hysteresis. A comprehensive electrical response of the PSCs is investigated. The bias‐dependent electrochemical impedance spectroscopy (EIS) reveals the appearance of the negative capacitance in the low‐frequency regime. The modification of the low‐frequency PSCs response accompanied by a further decrease in recombination resistance is due to the interfacial interactions between the migrating ions and the metal contact. The doped and undoped P3HT layers impede this interaction which explains the absence of the negative capacitance at lower applied voltages. The investigation provides an understanding of the physical processes behind the negative capacitance.