Ordered charge transport in supramolecular assemblies for enhancing the performance of HTL-free carbon-based perovskite solar cells

Abstract

The crystallization degree of perovskite (PVK) crystals is vital for solar cell efficiency, as it affects charge carrier transport. Researchers are using organic molecules to improve PVK crystallization, but face challenges with charge transport efficiency at interfaces due to the principle of maximum entropy. Here, living supramolecular assemblies (LSA) were prepared in the two-dimensional confined space of layered double hydroxide (LDH). The carbonyl (CO) functional groups in LSA assembled from terephthalic acid (TPA) coordinated with the uncoordinated Pb²⁺ ions in the PVK light-absorbing layer, passivating grain boundary defects. Importantly, the ordered charge transport in LSA can decrease the carrier complexation, which are commonly the main causes of charge carrier recombination and the decline in device performance. Thus, following the addition of TPA-LSA, carbon-based perovskite solar cells (PSCs) processed entirely in air achieved a maximum photoelectric conversion efficiency (PCE) of 13.86 %. This work provides an effective strategy for the enhancing the efficiency PSCs by using the supramolecular materials.