Complementary Absorbing Star‐Shaped Small Molecules for the Preparation of Ternary Cascade Energy Structures in Organic Photovoltaic Cells. (23rd October 2012)

• Record Type: Journal Article
• Authors: Cha, Hyojung; Chung, Dae Sung; Bae, Suk Young; Lee, Min‐Jung; An, Tae Kyu; Hwang, Jihun; Kim, Kyung Hwan; Kim, Yun‐Hi; Choi, Dong Hoon; Park, Chan Eon
• Is Part Of: Advanced functional materials. Volume 23:Number 12(2013)
• Page Start: 1556
• Page End: 1565
• Publication Date: 2012-10-23
• Subjects: Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201201913
• Languages: English
• ISSNs: 1616-301X

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Two anthracene‐based star‐shaped conjugated small molecules, 5′, 5″‐(9, 10‐bis((4‐hexylphenyl)ethynyl)anthracene‐2, 6‐diyl)bis(5‐hexyl‐2, 2′‐bithiophene), HBantHBT, and 5′, 5″‐(9, 10‐bis(phenylethynyl)anthracene‐2, 6‐diyl)bis(5‐hexyl‐2, 2′‐bithiophene), BantHBT, are used as electron‐cascade donor materials by incorporating them into organic photovoltaic cells prepared using a poly((5, 5‐E‐alpha‐((2‐thienyl)methylene)‐2‐thiopheneacetonitrile)‐alt‐2, 6‐[(1, 5‐didecyloxy)naphthalene])) (PBTADN):[6, 6]‐phenyl‐C71‐butyric acid methyl ester (PC<sub>71</sub>BM) blend. The small molecules penetrate the PBTADN:PC<sub>71</sub>BM blend layer to yield complementary absorption spectra through appropriate energy level alignment and optimal domain sizes for charge carrier transfer. A high short‐circuit current (<italic>J</italic><sub>SC</sub>) and fill factor (FF) are obtained using solar cells prepared with the ternary blend. The highest photovoltaic performance of the PBTADN:<bold>BantHBT</bold>:PC<sub>71</sub>BM blend solar cells is characterized by a <italic>J</italic><sub>SC</sub> of 11.0 mA cm<sup>−2</sup>, an open circuit voltage (<italic>V</italic><sub>OC</sub>) of 0.91 V, a FF of 56.4%, and a power conversion efficiency (PCE) of 5.6% under AM1.5G illumination (with a high intensity of 100 mW<sup>−2</sup>). The effects of the small molecules on the ternary blend are investigated by comparison with the traditional poly(3‐hexylthiophene) (P3HT):[6, 6]‐phenyl‐C61‐butyric acid methyl ester (PC<sub>61</sub>BM) system.</p> </abstract>