Effect of spray deposition time on optical and morphological properties of P3HT: PCBM thin films

This paper investigated the effect of spray deposition time on optical and morphological properties of p3ht: pcbm thin films. the effects of spray deposition time on the optical and morphological properties of thin films were investigated using optical microscopy,uv-vis spectrophotometry and atomic force microscopy (afm). the afm spectra show that the thin films prepared at 10s spray deposition time are more uniform while the 15s and 20s samples presented coffee ring shapes with inhomogeneous surface formation. the ridge-like features can be observed in the surface for all samples and become more pronounced with increasing spray deposition time. the root mean square (rms) roughness of the samples increased with increasing spray deposition time. based on the absorption results,it is concluded that higher spray coating times result in lower crystallinity of the thin film. the 10 s spray deposition time is the most suitable deposition time for producing thin films with good morphology and crystallinity for polymer solar cells (pscs) with improved power conversion efficiency (pce). © 2015 penerbit utm press. all rights reserved.