• 3D PV cells;
  • 3D photosensor;
  • sol–gel method;
  • wire-shaped cells

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. pssa201330245-gra-0001