2,5-Thiophene Substituted Spirobisiloles - Synthesis, Characterization, Electrochemical Properties and Performance in Bulk Heterojunction Solar Cells

Kassem Amro (1) , Anil K. Thakur (2) , Joëlle Rault-Berthelot (3) , Cyril Poriel (3) , Lionel Hirsch (2) , William Elliott Douglas (1) , Philippe Gerbier (1) , Sébastien Clément (1)

1 ICGM ICMMM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
2 IMS - Laboratoire de l'intégration, du matériau au système
3 ISCR - Institut des Sciences Chimiques de Rennes

New spirobisilole molecules containing thienyl (DTSBS) and bis-thienyl (BBTSBS) electron donor groups have been synthesized for use as the donor material in bulk-heterojunction solar cells together with PCBM. The spectroscopic, electrochemical and thermal properties of DTSBS and BBTSBS have been investigated. All these new spirobisiloles exhibit excellent thermal stability. Cyclic voltammetry measurements revealed reversible and irreversible oxidation and irreversible reduction processes. The highest occupied and lowest unoccupied molecular orbital (HOMO/LUMO) energy levels were determined from electrochemical measurements and DFT calculations. The HOMO/LUMO energy levels were estimated to lie in the range -5.2 to -2.3 eV for DTSBS and -4.9 to -2.6 eV for BBTSBS. For both compounds, electropolymerization processes occur at potentials higher than 1.5 V leading to low band gap electrogenerated polymers. Spin-coating-deposited bulk-heterojunction solar cells fabricated with the novel spirobisiloles as donor and PCBM as acceptor displayed open-circuit voltages up to 0.4 V, short-circuit currents around 0.5 mA.cm-2, and power conversion efficiencies approaching 0.1 %.

Mots clés: solar cells; spirobisilole; electrochemistry; AIE

Domaines: Chimie organique; Matériaux; Chimie théorique et/ou physique

Kassem Amro, Anil K. Thakur, Joëlle Rault-Berthelot, Cyril Poriel, Lionel Hirsch, et al.. 2,5-Thiophene Substituted Spirobisiloles - Synthesis, Characterization, Electrochemical Properties and Performance in Bulk Heterojunction Solar Cells. New Journal of Chemistry, 2013, 37, pp.464-473. ⟨10.1039/C2NJ40535K⟩. ⟨hal-00748958⟩