The impact of laser-target absorption depth on the surface and internal morphology of matrix-assisted pulsed laser evaporated conjugated polymer thin films

Poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-(1-cyanovinylene)-phenylene] (MEH-CN-PPV) thin films were deposited using resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) from targets comprising differing ratios of phenol to ice to assess the impact of laser-target absorption depth on film morphology. The surface and internal morphologies of as-deposited and annealed films indicate that the RIR-MAPLE process can be tuned to favor ablation with more or less vaporous ejecta by tuning the laser-target absorption depth. The demonstrated ability to tune between more or less vaporous ejecta strongly impacts the subsequent morphologies of the deposited films, and has important implications to realizing optoelectronic devices using the RIR-MAPLE process.