Morphological and crystalline characterization of pulsed laser deposited pentacene thin films for organic transistor applications

Highlights: • Pulsed laser deposition of pentacene thin films without chemical degradation of the molecules. • Correlation between deposition parameters and orientation of pentacene molecules in ordered or disordered phase. • The resulting phase turns out to be dependent of the underlying layer. - Abstract: We show that high-quality pentacene (P5) thin films of high crystallinity and low surface roughness can be produced by pulsed laser deposition (PLD) without inducing chemical degradation of the molecules. By using Raman spectroscopy and X-ray diffraction measurements, we also demonstrate that the deposition of P5 on Au layers result in highly disordered P5 thin films. While the P5 molecules arrange within the well-documented 1.54-nm thin-film phase on high-purity fused silica substrates, this ordering is indeed destroyed upon introducing an Au interlayer. This observation may be one explanation for the low electrical performances measured in P5-based organic thin film transistors (OTFTs) deposited by laser-induced forward transfer (LIFT).