Ultra-Large Compressive Plasticity of E-Ga2O3 Thin Films at the Submicron Scale

Gallium oxide (Ga2O3) usually fractures in the brittle form, and achieving large plastic deformability to avoid catastrophic failure is in high demand. Here, epsilon-Ga2O3 thin films with columnar crystals and partial unoccupied Ga sites are synthesized, and it is demonstrated that the epsilon-Ga2O3 at the submicron scale can be compressed to an ultra-large plastic strain of 48.5% without cracking. The compressive behavior and related mechanisms are investigated by in situ transmission electron microscope nanomechanical testing combined with atomic-resolution characterizations. The serrated plastic flow and large strain burst are two major deformation forms of epsilon-Ga2O3 during compression, which are attributed to the dislocation nucleation and avalanches, formation of new grains, and amorphization. The ultra-large compressive plasticity of epsilon-Ga2O3 thin films at the submicron scale can inspire new applications of Ga2O3 in micro- or nano- electronic and optoelectronic devices, especially those that require impact resistance during processing or service.

Automated summary

In this study, epsilon-Ga2O3 thin films with columnar crystals and partial unoccupied Ga sites were synthesized, and it was found that the submicron-scale epsilon-Ga2O3 could withstand an ultra-large plastic strain without cracking. This discovery has important implications for the applications of Ga2O3 in micro- or nano-electronic and optoelectronic devices.