Improved optical quality of heteroepitaxially grown metal-organic framework thin films by modulating the crystal growth.

Fabricating high-quality thin films of metal-organic frameworks (MOFs) is important for integrating MOFs in various applications. Specifically, optical/electrical devices require MOF thin films that are crystallographically oriented, with closely packed crystals and smooth surfaces. Although the heteroepitaxial growth approach of MOFs on metal hydroxides has been demonstrated to control the orientation of the three crystallographic axes, the fabrication of MOF thin films with both three-dimensional crystallographic orientation and smooth surfaces remains a challenge.