Small Molecule Organic Semiconductors on the Move: Promises for Future Solar Energy Technology

TLDR

In recent years, organic solar cell research has intensified to develop new materials and improve tunability, processability, power‑conversion efficiency, and stability. The review, written from an organic chemist’s perspective, surveys small‑molecule and oligomer solar cells, focusing on planar‑ and bulk‑heterojunction devices, the design and performance of donor and acceptor materials, recent efficiency achievements, and strategies to boost efficiency. The review analyzes device architectures (planar‑ and bulk‑heterojunctions), the design and performance of donor and acceptor small‑molecule materials, and strategies for efficiency enhancement. The review summarizes efficiencies achieved with small‑molecule and oligomer organic solar cells, highlighting the materials and device concepts developed over the past decade.

Abstract

This article is written from an organic chemist's point of view and provides an up-to-date review about organic solar cells based on small molecules or oligomers as absorbers and in detail deals with devices that incorporate planar-heterojunctions (PHJ) and bulk heterojunctions (BHJ) between a donor (p-type semiconductor) and an acceptor (n-type semiconductor) material. The article pays particular attention to the design and development of molecular materials and their performance in corresponding devices. In recent years, a substantial amount of both, academic and industrial research, has been directed towards organic solar cells, in an effort to develop new materials and to improve their tunability, processability, power conversion efficiency, and stability. On the eve of commercialization of organic solar cells, this review provides an overview over efficiencies attained with small molecules/oligomers in OSCs and reflects materials and device concepts developed over the last decade. Approaches to enhancing the efficiency of organic solar cells are analyzed.