Reconfiguration of band-edge states via intermolecular packing in organic semiconductor-incorporated perovskites

Abstract

Organic semiconductor-incorporated perovskites (OSiPs) have been intensively investigated owing to their superior optoelectronic features and enhanced stability. However, the effects of intermolecular packing on their interplays with perovskites and how these interplays impact the electronic and optical properties of OSiPs remain unclear. Here, we report a new strategy for tunable interlayer interactions in OSiPs by introducing the proper intermolecular packing of thiophene-based isostructural polymorphs, which can mainly be classified into two main types: L-parallel and X-herringbone packing modes. This strategy can be adaptable to varied π-conjugation lengths and perovskite layers, enabling the reconfiguration of band-edge states and tunable band alignment types. The well-matched energy landscape of the band edges between the X and L configurations could serve as a cascade type-II heterojunction for the hole-transporting layer (HTL), facilitating efficient hole extraction and reducing energy loss during perovskite solar cells (PSCs) operation. This study underscores the importance of intermolecular interactions in adjusting the electronic properties, paving the way for the next generation of novel perovskite optoelectronic devices through molecular engineering.