Preparation and processing of electrochemically deposited TiO2 film into a heterojunction photovoltaic device

Abstract

Preparation and optical study of the electrochemically deposited TiO2 thin film on the FTO glass and its processing and feasibility to construct a hetero-junction hybrid solar cell device based on an n-type inorganic (TiO2) and a p-type organic (P3HT) film has been elucidated. A promising initial efficiency of 0.18% with a JSC value of 3.1mAcm -2 , VOC of 0.4V and a fill factor of 34% under AM 1.5G (100 mW/cm 2 ) condition has been achieved. The cross sectional SEM results shows a film thickness of inorganic and organic layers of ~900 nm and ~200 nm, respectively. The XRD results shows that the grown inorganic film possess a reduced titania peaks at 2θ of 27° and 28° which after calcination to 450°C for 1h in ambient, transform to pure anatase crystal structure. The observed efficiency can be attributed to the formation of a good hetero-structure of TiO2/P3HT films, the percolation of electron and holes towards the respective electrodes efficiently due to inorganic-organic nature of the thin films. The efficiency may likely to be improved and electron injection can be augmented by the suitable band alignment with hierarchical placement of thin buffer layers. The details of device properties were analyzed by SEM, XRD, AFM, UVVis, J-V and EQE techniques.