Abstract
A donor-acceptor (D-A) type indoline dye, D149, was used as an electron donor in solution-processed organic solar cells (OSCs). For bulk-heterojunction (BHJ) type OSCs with PC70BM as electron acceptor, the power conversion efficiency (PCE) is sensitive to the amount of D149 in the D149/PC70BM blend film. When the concentration of D149 in the blend film was as low as 5%, the highest PCE of up to 1.29%, together with a short-circuit current density (Jsc) of 4.58 mA·cm−2, an open-circuit voltage (Voc) of 0.90 V and a fill factor (FF) of 0.31, was achieved. In order to improve the PCE of D149-based OSCs, a bilayer-heterojunction configuration with C70 as electron acceptor has been employed. By optimizing the thickness of the D149 layer and varying the electron- and hole-transport layers, a highest PCE of up to 2.28% with a Jsc of 4.38 mA·cm−2, a Voc of 0.77 V, and an FF of 0.62 was achieved under AM 1.5G solar illumination (100 mW·cm−2).
Highlights
Organic solar cells (OSCs) have been regarded as one of the major alternatives to the traditional silicon-based photovoltaics, owning to their potential low-cost and short energy pay-back time [1,2,3,4].In OSCs, the photon-induced charge carriers are always generated at the interface between the p-type electron donor and n-type electron acceptor, and is followed by complicated charge transfer processes
Unlike most n-type materials that focus on fullerene and their derivatives, p-type materials offer more variability, including polymers and small molecules, and the highest power conversion efficiencies (PCE) for OSCs based on polymers and small molecules have been continuously improved [5,6,7,8,9,10]
The D-A type of molecular architecture is very effective at producing low band-gap materials where the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels can be controlled and this has become a common approach for the design of materials with broad absorption for use in organic solar cells
Summary
Organic solar cells (OSCs) have been regarded as one of the major alternatives to the traditional silicon-based photovoltaics, owning to their potential low-cost and short energy pay-back time [1,2,3,4]. The D-A type of molecular architecture is very effective at producing low band-gap materials where the HOMO and LUMO levels can be controlled and this has become a common approach for the design of materials with broad absorption for use in organic solar cells. It is a very effective way to tailor molecular donors as evidenced by the numerous reports on this type of material published in recent years [11,12]. To the best of our knowledge, this is the first time that a highly efficient DSC dye sensitizer has been directly employed as the electron donor for both bulk- and bilayer-heterojunction OSCs
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.