Study of Optical and Photovoltaic Properties of N-Alkyl Substituted Polycarbazole Derivative and Its Copolymer with Thiophene

Abstract

Poly(9-dodecylcarbazole) (PDDC) and poly[(9-dodecylcarbazole)-co-thiophene] (PDDCT) were studied for optical and electrochemical properties and found the polymers as promising material to be used for the solar cell. The electrochemical band gap for the polymers PDDC and PDDCT were calculated to be 2.21 eV and 1.91 eV, respectively. The absorption spectra showed broad absorption over the wavelength range of 350–590 nm with maximum absorptions at 414 and 443 nm (λ_max), respectively, for PDDC and PDDCT. The polymeric photovoltaic cells based on blend of polymer and TiO₂ nanoparticles were fabricated and the power conversion efficiency (PCE) of the photovoltaic cells were measured to be 0.11% and 0.14%, respectively, for PDDC and PDDCT, and improved the same up to 0.18% and 0.24% upon annealing of the active layer films at 150°C for 30 minutes.

Keywords:

• Acceptor
• Annealing
• Efficiency
• Hybrid
• Nanoparticles
• Optical
• Photovoltaic
• Polycarbazole

Notes

^a Φ_ox and Φ_red are the onset oxidation and reduction potential calculated from cyclic voltammogram [20].

^b The optical band gap was obtained from empirical formula, E_g = 1240/λ_edge, in which λ_edge is the onset value of the absorption spectrum in the longer wavelength direction.