An organic solar cell based on poly (3-hexathiophine-2,5-diyl) and [6,6]-phenyl C61 butyric acidmethyl ester has
been subjected to all layers treatment andwas investigated for combined effects of the these layers on device performance.
These treatment included optimization of active layer morphology and thickness and improving the
structure of the hole and electron transport layers, as well as subjecting the full device to optimum post deposition
thermal treatment. Such a device has shown an increase in the optical absorption intensity in the near infrared
region compared to the reference device, which is thought to be advantageous for producing high current
density. The increase in the current density has also been correlated with light trapping within the active layer
and the possibility of the occurrence of total internal reflection, which was explained using total internal reflection
spectroscopic ellipsometrymeasurements. The current density-voltage characteristics have been measured
in dark and under illumination. Power conversion efficiency as high as 7% has been achieved correlatedwith a fill
factor of 71%.