Abstract
Flexible electronic devices need to survive bending or stretching operation without mechanical failure. If inorganic thin films are involved in the device structure, the evolution of cracks is a major challenge to overcome. Here, we report a novel way to substantially improve the fracture behavior of films that are based on intentional utilization of residual stress on the films by in situ sputtering on a stretched polymer substrate. The in situ sputtering combined with a stabilization stage yielded ZnO:Al thin films with a nearly 2-fold improvement in crack initiation strain, which indicates greater resistance to bending. The critical strain of the optimal ZnO:Al films was ∼1.83%, which is a significant improvement compared to the current tolerance value of ∼1%. This was accompanied by a ∼300% improvement in fracture energy. We attributed the improved fracture behavior to the presence of residual compressive stresses, which creates a barrier for crack formation by acting opposite to the applied bending strain.
| Original language | English |
|---|---|
| Pages (from-to) | 14654-14659 |
| Number of pages | 6 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 7 |
| Issue number | 27 |
| DOIs | |
| Publication status | Published - 2015 Jul 15 |
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
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Prestress Driven Improvement in Fracture Behavior of in Situ Sputtered Zinc Oxide Thin Films on Stretched Polymer Substrates. / Choi, Hong Rak; Eswaran, Senthil Kumar; Cho, Yong Soo.
In: ACS Applied Materials and Interfaces, Vol. 7, No. 27, 15.07.2015, p. 14654-14659.Research output: Contribution to journal › Article
TY - JOUR
T1 - Prestress Driven Improvement in Fracture Behavior of in Situ Sputtered Zinc Oxide Thin Films on Stretched Polymer Substrates
AU - Choi, Hong Rak
AU - Eswaran, Senthil Kumar
AU - Cho, Yong Soo
PY - 2015/7/15
Y1 - 2015/7/15
N2 - Flexible electronic devices need to survive bending or stretching operation without mechanical failure. If inorganic thin films are involved in the device structure, the evolution of cracks is a major challenge to overcome. Here, we report a novel way to substantially improve the fracture behavior of films that are based on intentional utilization of residual stress on the films by in situ sputtering on a stretched polymer substrate. The in situ sputtering combined with a stabilization stage yielded ZnO:Al thin films with a nearly 2-fold improvement in crack initiation strain, which indicates greater resistance to bending. The critical strain of the optimal ZnO:Al films was ∼1.83%, which is a significant improvement compared to the current tolerance value of ∼1%. This was accompanied by a ∼300% improvement in fracture energy. We attributed the improved fracture behavior to the presence of residual compressive stresses, which creates a barrier for crack formation by acting opposite to the applied bending strain.
AB - Flexible electronic devices need to survive bending or stretching operation without mechanical failure. If inorganic thin films are involved in the device structure, the evolution of cracks is a major challenge to overcome. Here, we report a novel way to substantially improve the fracture behavior of films that are based on intentional utilization of residual stress on the films by in situ sputtering on a stretched polymer substrate. The in situ sputtering combined with a stabilization stage yielded ZnO:Al thin films with a nearly 2-fold improvement in crack initiation strain, which indicates greater resistance to bending. The critical strain of the optimal ZnO:Al films was ∼1.83%, which is a significant improvement compared to the current tolerance value of ∼1%. This was accompanied by a ∼300% improvement in fracture energy. We attributed the improved fracture behavior to the presence of residual compressive stresses, which creates a barrier for crack formation by acting opposite to the applied bending strain.
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U2 - 10.1021/acsami.5b01836
DO - 10.1021/acsami.5b01836
M3 - Article
VL - 7
SP - 14654
EP - 14659
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 27
ER -