Progress of Organic Photovoltaic Materials Based on Indacenodithiophene and Its Derivatives

Abstract

Indacenodithiophene (IDT)) and its derivatives have been widely used in the design of organic photovoltaic materials and have made great breakthrough in recent years, due to their advantages of unique planar structure, thermal and light stability, and easy modification. In this review, these materials are summarized and classified according to the molecular structures, polymer or small molecule. The relationships between photovoltaic properties and the molecular structures are analyzed systematically, and the development tendency and prospects for future application are discussed.

Elevated Photovoltaic Performance in Medium Bandgap Copolymers Composed of Indacenodi-thieno[3,2-b]thiophene and Benzothiadiazole Subunits by Modulating the π-Bridge

“…Consequently, it was of significant importance and highly essential to explore the new MBG and WBG copolymers and make a thorough inquiry of the structure-performance relationship.Recently, highly coplanar aromatic/heteroaromatic units have attracted tremendous interest, because they possessed the following characteristics: (i) the elongated effective conjugation and improved overlap of π-orbitals along the polymer backbone direction in order to facilitate electron delocalization, which was instrumental in gaining a red-shifted absorption spectra to capture sunlight; (ii) the better intermolecular charge carrier hopping and restrained the interannular rotation so as to reduce the Marcus reorganization energy that could affect the rate of charge hopping, leading to an improved intrinsic charge mobility [22,24,[35][36][37]. One representative ladder-type penta-ring indacenodithiophene (IDT) unit, by covalently fusing the outer thiophene rings into the central benzene core, has gained tremendous interest because of the following merits: (i) better coplanarity, highly electron density originated from large fused system, and desirable mobility; (ii) the bridge carbon (sp 3 hybridization) which can be easily replaced by the heteroatoms such as Si, Ge, N, and S; (iii) multiple sites which can bond different side chain to ensure good solubility and solution-processability [37][38][39][40]. Therefore, substantial IDT-based and IDT-extended hepta-ring indacenodithieno[3,2-b]thiophene (IDTT)-based CPs have been developed [41][42][43][44][45][46][47][48][49].…”

Design, Synthesis, and Application in OFET of a Quinoxaline-Based D-A Conjugated Polymer

“…With its excellent planar symmetric structure, it can effectively promote intermolecular charge transfer. Thus, the devices prepared by this structure usually have excellent charge carrier mobility ( Cai et al, 2014 ; Zhai and Zhou, 2016 ). Recent research has reversed that IDT has become a widely used feeder structure for photovoltaic materials, especially in organic solar cells (OPV), which can provide an energy conversion efficiency of over 9.21% ( Andrew et al, 2020 ).…”