Solar cells utilizing small molecular weight organic semiconductors

TLDR

Typical materials, growth techniques, and device stability are critical for commercializing low‑cost, high‑performance organic solar cells. This review focuses on organic photovoltaic cells based on small molecular weight materials. The review explains photocurrent generation mechanisms and describes architectures such as donor–acceptor heterojunctions, exciton blocking layers, bulk heterojunctions, and stacked or tandem cells. The authors demonstrate that selecting materials with appropriate energy levels and absorption spectra influences open‑circuit voltage and short‑circuit current density. © 2007 John Wiley & Sons, Ltd.

Abstract

Abstract In this review, we focus on the field of organic photovoltaic cells based on small molecular weight materials. In particular, we discuss the physical processes that lead to photocurrent generation in organic solar cells, as well as the various architectures employed to optimize device performance. These include the donor–acceptor heterojunction for efficient exciton dissociation, the exciton blocking layer, the mixed or bulk heterojunction, and the stacked or tandem cell. We show how the choice of materials with known energy levels and absorption spectra affect device performance, particularly the open‐circuit voltage and short‐circuit current density. We also discuss the typical materials and growth techniques used to fabricate devices, as well as the issue of device stability, all of which are critical for the commercialization of low‐cost and high‐performance organic solar cells. Copyright © 2007 John Wiley & Sons, Ltd.