Bi2Te3/Sb(2)Te(3-)graphene bidirectional heterostructures: Enhancement of optical nonlinearity and short pulse generation of solid-state laser

To overcome the application limitations of the individual 2D materials, the Bi2Te3/Sb2Te3-Graphene (BTST-G) bidirectional heterostructures (BHSs) with high crystallinity and significantly enhance optical properties are constructed by a simple self-assembly solvothermal method for the first time. The BHSs not only combine the narrower band gap, larger modulation depth of BTST but also integrate the higher carrier mobility of graphene, enabling them to be excellent absorbers (SAs) for ultra-short-pulse laser technology. This paper further demonstrates that the stable passively Q-switched laser operation can be self-started immediately at a relatively low threshold power of 50 mW using the BTST-G BHSs. The shortest pulse width of 160 ns with a repetition rate of 1026 kHz is obtained, corresponding to the pulse energy of 2.0 & mu;J and the output power of 2.043 W. Compared with the ST-G, BT-G, the peak power increases 2 times and the pulse width is compressed by 66%. This work paves the way for future fabrication of unprecedented 2D heterostructures for application in pulse laser and other research which will bring more opportunities and challenges for the development of science technology and industry.

Automated summary

The Bi2Te3/Sb2Te3-Graphene (BTST-G) bidirectional heterostructures (BHSs) are constructed for the first time by a self-assembly solvothermal method, which overcome the application limitations of individual 2D materials. The BHSs combine the advantages of BTST and graphene, making them excellent absorbers for ultra-short-pulse laser technology.