Tetrapropyl-tetraphenyl-diindenoperylene derivative as a green absorber for high-voltage stable organic solar cells

Journal article

We present small molecule organic solar cells (SMOSC) based on flat heterojunctions (FHJ) of the alternative green donor 2,3,10,11-tetrapropyl-1,4, 9,12-tetraphenyl-diindeno[1,2,3-cd:1′,2′,3′-lm]perylene (P4-Ph4-DIP) and the fullerene C₆₀. P4-Ph4-DIP absorbs in the green spectral range and thus fills the spectral gap that standard absorber materials (zinc or copper phthalocyanine for red and C₆₀ for blue absorption) leave, thus allowing broad coverage of the sun spectrum, which is of major interest for tandem devices. The materials properties of P4-Ph4-DIP are studied, and SMOSC are characterized by current voltage, external quantum efficiency, and aging measurements. The solar cells display very high fill factors FF > 76% and open circuit voltages V_OC of close to 1 V. Mismatch-corrected efficiencies of up to 1.9% are obtained. Aging measurements show that C₆₀ in conjunction with P4-Ph4-DIP yields extremely stable devices. We observe ≈ 88% of the initial efficiency after 2500 h illumination at 999 mW/cm² illumination intensity, with no observable change in short-circuit current density. Furthermore, we also show that a systematic variation of donor thickness in FHJ can be combined with transfer matrix formalism-based optical simulations and the continuity equation for excitons to reliably determine the exciton diffusion length L_D. A value of 9 ± 1 nm is found for P4-Ph4-DIP. © 2011 American Physical Society.

Authors: Meiss, J; Hermenau, M; Tress, W; Schuenemann, C; Selzer, F

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review B - Condensed Matter and Materials Physics
• Volume: 83
• Issue: 16
• Publication date: 2011-04-11
• DOI: 10.1103/PhysRevB.83.165305
• EISSN: 1550-235X
• ISSN: 1098-0121
• Language: English