Phthalimide and Naphthalimide end‐Capped Diketopyrrolopyrrole for Organic Photovoltaic Applications. Issue 9 (29th June 2017)

• Record Type: Journal Article
• Authors: Chen, Ming; Du, Chenchen; Ren, Xiaolei; Yi, Maoheng; Yi, Jinduo; Chen, Chufeng; Liu, Feng; Li, Minjie; Ma, Changqi; Wang, Hongyu
• Is Part Of: Chinese journal of chemistry. Volume 35:Issue 9(2017)
• Page Start: 1396
• Page End: 1404
• Publication Date: 2017-06-29
• Subjects: diketopyrrolopyrrole -- phthalimide -- naphthalimide -- organic solar cells -- non‐fullerene acceptor; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cjoc.201700068
• Languages: English
• ISSNs: 1001-604X

Abstract

Abstract : Two small molecules namedPI‐DPP andNI‐DPP with a DPP core as the central strong acceptor unit and phthalimide/naphthalimide as the terminal weak acceptor were designed and synthesized. The effects of terminal phthalimide/naphthalimide units on the thermal behavior, optical and electrochemical properties, as well as the photovoltaic performance of these two materials were systematically studied. Cyclic voltammetry revealed that the lowest unoccupied molecular orbitals (LUMO) (~ ‐3.6 eV) of both molecules were intermediate to common electron donor (P3HT) and acceptor (PCBM). This indicated thatPI‐DPP andNI‐DPP may uniquely serve as electron donor when blended with PCBM, and as electron acceptor when blended with P3HT, where sufficient driving forces between DPPs and PCBM, as well as between P3HT and DPPs should be created for exciton dissociation. Using as electron donor materials, PI‐DPP andNI‐DPP devices exhibited low power conversion efficiencies (PCEs) of 0.90% and 0.76% by blending with PCBM, respectively. And a preliminary evaluation of the potential of theNI‐DPP as electron acceptor material was carried out using P3HT as a donor material, and P3HT:NI‐DPP device showed a PCE of 0.6%, with an open circuit voltage ( V OC ) of 0.7 V, a short circuit current density ( J SC ) of 1.91 mAcm ‐2, and a fill factor (FF) of 45%. Abstract : NI‐DPP can serve as both an electron donor and acceptor in blends with PC71 BM or P3HT, respectively.