A Short Review on Surface-Confined Monolayers of π-Conjugated Polymers for Photovoltaics

pi-conjugated polymer (CPs)-functionalized semiconductor surfaces are important components of photovoltaic (PV) devices. In this context, the use of surface-confined monolayers (SCMs) of CPs has attracted great attention due to their operational stability, reliability, and excellent control over the nanostructure and morphology of CP films. The CPs with proper anchoring groups are covalently bonded to the semiconductor surface driven by the interactions between anchors and substrate, forming densely packed and orderly assembled polymer chains in thin films. The nanostructure of CP SCMs is highly dependent on the type and position of anchors, polymer structure, and chain length, as well as the film-forming techniques. Herein, general features, anchoring mechanism, grafting approaches, and PV properties of CP SCMs are described and analyzed. Then, the applications of CP monolayers as photosensitizers for dye sensitized solar cells and hole transport interlayers for bulk-heterojunction polymer solar cells and perovskite solar cells are summarized. With the structure tunability, future study directions for CP SCMs in terms of structure effect, assembly states, and efficiency enhancement are discussed.

Automated summary

This paper discusses the importance of pi-conjugated polymer-functionalized semiconductor surfaces and the use of surface-confined monolayers of these polymers. The nanostructure of the monolayers is influenced by factors such as the type and position of anchor groups, polymer structure, and film-forming techniques. The applications of these monolayers in dye sensitized solar cells and polymer solar cells are summarized. Future research directions for improving the efficiency and assembly states of these monolayers are also discussed.