Effect of Kinetic Energy and Angle of Incidence on Sputtering of P3HT by Low-Energy Ar Projectiles

Molecular dynamics computer simulations investigate the effect of kinetic energy and impact angle on the sputtering process of poly(3-hexylthiophene) (P3HT) induced by Ar projectiles. The influence of these parameters on the projectile penetration depth, efficiency of particle ejection, as well as chemical and structural damage is probed. The observed variations can be attributed to an interplay between the depth of deposited energy near the bombarded surface and the amount of primary kinetic energy carried away by backscattered projectiles. The scope of damage is predominantly restricted to the depth of the projectile’s penetration, depending on the square root of the primary kinetic energy and the cosine of the impact angle. However, additional damage induced by collisions with energized sample atoms is also observed. Projectiles that remain in the sample tend to agglomerate at the interlayer spacings. The chemical damage is predominantly created in the alkyl chain. The implications of the current work for the SIMS/SNMS analysis of P3HT by low-energy Ar projectiles are discussed.