In situ 3-hexylthiophene polymerization onto surface of TiO2 based hybrid solar cells

Abstract

A novel configuration of hybrid solar cells fabricated using TiO2 and in situ polymerization of poly(3-hexylthiophene), or P3HT, on the surface of TiO2 is reported. Comparison of UV–Vis absorption and current/voltage (I/V) characteristics of devices with or without in situ polymerized P3HT layer were discussed, and the surface morphology of TiO2/in situ polymerized P3HT film was investigated by AFM in the contact mode. The short-circuit current density and energy conversion efficiencies of device with in situ polymerized P3HT layer were higher by 6 times and 3 times compared to that of device without the in situ polymerized P3HT layer. By adding poly (ethylene dioxythiophene)-poly (styrene sulfonic acid)(PEDOT-PSS) layer under the top contact, device showed a short-circuit current density of 1.27 mA cm−2, an open-circuit voltage of 0.52 V, a fill factor of 0.24, and a energy conversion efficiency of 0.16% at AM 1.5 solar illumination (100 mW cm−2).