Estimation of trap energy of fuchsin dye sensitized Organic Photovoltaic Device based on Titanium Dioxide (TiO2)

Abstract

Recently, dye sensitized photovoltaic cell plays an important role as a renewable source of energy because of low material cost, easy processing techniques. But the organic devices are prone to traps due to which charge carriers get trapped or recombined within the device before collection at the electrodes. So traps limit the device performance. The study on the charge transport mechanism enables us to estimate this trap energy. In this work, we have designed the photovoltaic device and estimated the trap energy of inexpensive water-soluble Fuchsin dye based photovoltaic cells. To design a photovoltaic device we have used ITO as a front electrode and copper as a back electrode. 540mg of TiO2 nanoparticles and 100mg of Fuchsin dye mixed well in N, N-Dimethyl formamide (DMF). A thin layer of this TiO2 nanoparticles and dye has been deposited between two electrode using popular method named doctor’s blade method. A drop of electrolyte made of lithium percolate (LiClO4), ethylene carbonate (EC) and propylene carbonate (PC) solution has been used to obtain better device performance. The analysis of dark current density- voltage (J-V) characteristics using exponential charge transport mechanism of this photovoltaic cell the trap energy has been calculated 0.5399 ± 0.006 eV. Also, we have observed photovoltaic effect of this device. Under illumination of 120 kLUX intensity, maximum short circuited current density is obtained 4.62 μA/cm2 and open circuited voltage is 0.24 Volt.