Benzodithiophenedione-based polymers: recent advances in organic photovoltaics

Abstract

Over the past 20 years, significant progress has been made in organic photovoltaics (OPVs) due to its advantages of being cost-effective, being lightweight, and having flexible manufacturability. The optical-active layer of OPVs consists of a p-type polymer as the donor and an n-type small molecule as the acceptor. An efficient design strategy of a polymer donor is based on an alternating electron-donating unit (D) and an electron-accepting unit (A). Among numerous electron-accepting units, an emerging annelated thiophene of benzodithiophenedione (BDD) has exhibited a distinguished photovoltaic performance because of its planar molecular structure, low-lying highest occupied molecular orbit (HOMO) level and good self-assembly property. In this review article, we summarize the most recent developments in BDD-based photovoltaic materials. Special attention is paid to the chemical structure-property relationships, such as the absorption, bandgap, energy levels, mobilities, and photovoltaic performances. The empirical regularities and perspectives on the future development of BDD-based photovoltaic materials are included.

Layer-by-layer fabrication of organic photovoltaic devices: material selection and processing conditions

“…6, b41-43). 116 Fig. 6, b42) which achieved a PCE above 16% when paired with Y6 in a LbL OPV device.…”

Hot-carriers in organic photovoltaics

“…with planar backbone, the timescale as well as energetics of planarization will be modified and the absorbed energy can be utilized completely for carrier generation at higher V oc . Indeed recent studies have found reduced voltage loss and increment in PCE by choosing planar backbone organic semiconductors [19,20]. In-detail studies on correlating backbone planarity with carrier relaxation and photovoltaic performance will help to minimize loss channels in OPVs.…”

Over 14% Efficiency Single‐Junction Organic Solar Cells Enabled by Reasonable Conformation Modulating in Naphtho[2,3‐b:6,7‐b′]difuran Based Polymer

“…Bulk heterojunction (BHJ) organic solar cells (OSCs) have been in favorable development in recent years, on account of their adjustable structure, flexibility, low cost, and more. [ 1–6 ] The joint advantages result in power conversion efficiencies (PCEs) of the state‐of‐the‐art photovoltaic devices over 17%. [ 7–12 ] The development of p‐type polymer donors plays a crucial role in the improvement of the photovoltaic performance.…”