Highly efficient organic solar cells based on a poly(2,7-carbazole) derivative

• Published in: Journal of materials chemistry Vol. 19; no. 30; pp. 5351 - 5358
• Main Authors: WAKIM, Salem, BEAUPRE, Serge, BLOUIN, Nicolas, AICH, Badrou-Réda, RODMAN, Sheila, GAUDIANA, Russell, YE TAO, LECLERC, Mario
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2009
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Energy; Exact sciences and technology; Natural energy; Photovoltaic conversion; Physics; Solar cells. Photoelectrochemical cells; Solar energy; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Transport properties; Carbazole derivatives; Active layer; Frequency conversion; Polymer; Charge transport; Layer thickness; Solar cell; Transport process; Multiphase system; Illumination; Light absorption; Molecular mass; Heterostructures; Heterojunction
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/b901302d

We have studied the utilization of PCDTBT, an alternating poly(2,7-carbazole) derivative, in organic bulk heterojunction solar cells. The effect of polymer molecular weight, PCDTBT:[60]PCBM ratio, and active layer thickness on the device performance is reported. The best performance was obtained when the number-average molecular weights (M(n) are around 20 kDa with a polydispersity index around 2.2. Both PCDTBT:[60]PCBM ratio and active layer thickness affect the light absorption and the charge transport properties. By optimizing these two parameters, power conversion efficiency (PCE) up to 4.35% was reached under calibrated AM1.5G illumination of 100 mW cm(-2). When blended with [70]PCBM, PCDTBT exhibited a PCE up to 4.6%.