Synthesis of TCO-free Dye-sensitized Solar Cells with Nanoporous Ti Electrodes Using RF Magnetron Sputtering Technology

A new type of dye-sensitized solar cell (DSC) based on a porous type Ti electrode without using a transparent conductive oxide (TCO) layer is fabricated for low-cost high-efficient solar cell application. The TCO-free DSC is composed of a glass substrate/dye-sensitized TiO₂ nanoparticle/porous Ti layer/electrolyte/Pt sputtered counter electrode. The porous Ti electrode (~350 nm thickness) with high conductivity can collect electrons from the TiO₂ layer and allows the ionic diffusion of I⁻/I₃⁻ through the hole. The vacuum annealing treatment is important with respect to the interfacial necking between the metal Ti and porous TiO₂ layer. The efficiency of the prepared TCO-free DSC sample is about 3.5% (ff: 0.48, Voc : 0.64V, Jsc : 11.14 mA/ cm² ).