Tailoring the efficiency of 3D wire-shaped photovoltaic cells (WPVCs) by functionalization of solid-liquid interfacial properties

Abstract

An efficient 3D dye-sensitized photovoltaic microwire has been developed using thermally stable and highly conductive titanium microwires and carbon nanotube yarns (CNYs). Interaligned, ultrastrong, and flexible CNYs with excellent mechanical integrity and electrocatalytic property were successfully used as counter electrodes (CEs). The TiO2 nanophase coated Ti-microwire acts as the working electrode (WE). The CEs were twisted around the WE to collect and transmit the photogenerated electrons from the outer circuit. The interface in between photoactive TiO2 film and 3D conductive support has been optimized. The optimized 3D WPVC shows a 0.583% photon to energy conversion efficiency under an irradiation of AM 1.5 (100 mW cm -2). Cells with various lengths were observed to attain a fill factor (FF) above 0.8. This work tested WPVCs under different working environments to assess their engineering potential. A novel 3D wire-shaped photovoltaic cell (WPVC) is demonstrated. Carbon Nanotube Yarns (CNYs) are used to replace the metal-based counter electrode. The CNYs provide excellent interfacial and electrocatalytic properties. The WPVC shows an outstanding operational flexibility with efficient photovoltaic properties (e.g. FF above 0.8). These WPVCs are stable under different working environment. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.