Electronic Properties of Interfaces between PCPDTBT and Prototypical Electrodes Studied by Photoemission Spectroscopy

• Published in: Chemphyschem Vol. 12; no. 12; pp. 2345 - 2351
• Main Authors: Aygül, Umut, Peisert, Heiko, Frisch, Johannes, Vollmer, Antje, Koch, Norbert, Chassé, Thomas
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 22-08-2011; WILEY‐VCH Verlag; Wiley
• Subjects: Application fields; Applied sciences; conjugated polymers; Electrodes; electronic structure; Electrons; Energy; Energy-Generating Resources; Exact sciences and technology; Gold - chemistry; interfaces; Natural energy; organic solar cells; Photoelectron Spectroscopy; Photovoltaic conversion; Polyethylenes - chemistry; Polymer industry, paints, wood; Polymers - analysis; Polymers - chemistry; Polystyrenes - chemistry; Solar cells. Photoelectrochemical cells; Solar Energy; Surface Properties; Technology of polymers; Thiadiazoles - analysis; Thiadiazoles - chemistry; Tin Compounds - chemistry; photoelectron spectroscopy; interfaces; X ray; Organic solar cells; Thiadiazole derivatives; Experimental study; Conducting polymers; Polyelectrolyte; Interface structure; Electronic structure; Conjugated copolymer; Thiophene derivative polymer; Tin oxide; Styrenesulfonate polymer; Alternating copolymer; Photoelectron spectrometry; Thiophene derivative copolymer; conjugated polymers; Heterojunction
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201000999

We report on the electronic structure of poly[2,6‐(4,4‐bis‐ (2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7(2,1,3‐benzothiadiazole)] (PCPDTBT), a promising low‐band‐gap donor material for efficient bulk heterojunction organic solar cells. Electronic properties of interfaces formed between PCPDTBT and prototypical electrodes [Au, indium‐tin‐oxide and poly(ethylene‐dioxythiophene): poly(styrenesulfonate)], obtained from X‐ray photoemission spectroscopy and ultraviolet photoemission spectroscopy, are evaluated. The formation of interface dipoles is observed, and their consequences for device performance are discussed. For the system PCPDTBT/Au chemical interactions occur, which may affect in particular the charge extraction at the corresponding interface.
Mind the gap: The electronic properties of the promising low‐band‐gap polymer PCPDTBT and its interface properties with prototypical electrodes are investigated using X‐ray photoemission spectroscopy and ultraviolet photoemission spectroscopy. Photoemission studies reveal a chemical interaction between the polymer and gold (see picture).