Wavelength-tunable Zn1−xMgxO nanotube lasers on graphene films

Abstract

Wavelength-tunable lasers on various substrates, such as silicon and metal, are crucial for emerging optoelectronic applications such as photonic chip communication and biological optical probes. Here, we report on Zn1−xMgxO (0≤x≤0.07) nanotube lasers fabricated on graphene films. By using the ZnO nanotubes grown on graphene films as a template, core–shell Zn1−xMgxO/ZnO nanotube heterostructures can be fabricated. Blue-shifted laser emission is observed from Zn1−xMgxO nanotubes compared to ZnO, demonstrating wavelength tunability. Furthermore, the Zn1−xMgxO nanotube lasers can be lifted off from the original SiO2/Si substrate to be interfaced with a highly reflective Ag layer, resulting in enhanced lasing characteristics. Finally, finite-difference time-domain simulation is performed to investigate the lasing characteristics of Zn1−xMgxO nanotubes interfacing with air and Ag at one end face. This wavelength-tunable nanolaser on graphene provides a promising approach for fabricating high-performance and easily integrable lasers.