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Preventing Thin Film Dewetting via 2D Capping

Top: Dewetting suppression of a polystyrene (PS) thin film by an MoS2 capping layer. AFM height images before (left) and after (right) annealing at 180°C for 300s. Bottom: Dewetting suppression of a thin gold films by graphene capping layer. AFM height images with (left) and without (right) graphene (Gr) coverage.

Scientific Achievement
Demonstrated that a monolayer 2D capping layer with high Young’s modulus effectively suppresses dewetting of underlying polymer, metal, and organic semiconductor thin films.

Significance and Impact
Opens new opportunities to enhance the thermal stability and expands the processing parameters for thin film materials without significantly altering their physical properties.

Research Details

  • Universality of the capping approach was confirmed by transferring a single layer of 2-D materials such as graphene or MoS2, onto a film surface of polystyrene, semiconducting thienoazacoronene (EH-TAC) and gold.
  • Thermodynamic modeling indicated that the exceptionally high Young’s modulus and surface conformity of 2D capping layers substantially suppress surface fluctuations and thus dewetting.

P. Cao, P. Bai, A. A. Omrani, Y. Xiao, K. L. Meaker, H.-Z. Tsai, A. Yan, H. S. Jung, R. Khajeh, G. F. Rodgers, Y. Kim, A. S. Aikawa, M. A. Kolaczkowski, Y. Liu, A. Zettl, K. Xu, M. F. Crommie, T. Xu, Adv. Mater.  1701536 (2017)  DOI: 10.1002/adma.201701536