Role of carrier-transfer in the optical nonlinearity of graphene/Bi₂Te₃ heterojunctions

Abstract

Two-dimensional (2D) topological insulators (TIs) have attracted much attention owing to their striking optical nonlinearity. However, the ultra-low saturable intensity (SI) of TIs resulting from the bulk conduction band limits...

Bi2Te3/Graphene Heterostructure as the Saturable Absorber for ~1.0 μm Passively Q-switched Solid State Pulsed Laser

“…The relatively lager modulation depth and saturation intensity as well as the lower nonsaturable loss of Bi 2 Te 3 /graphene SA will be advantageous to the realization of high-performance Q-switched lasers. It is worth noting that the modulation depth and saturation intensity of the Bi 2 Te 3 /graphene SA in this work are comparable to those of the Bi 2 Te 3 /graphene SA produced by CVD [32]. A stable passive Q-switching laser operation was realized when the absorbed pump power was increased to be 2.86 W. The output power nearly increased linearly with the absorbed power elevated, and the maximum average output power of 305 mW with a slope efficiency of 11.7% was obtained until the absorbed power was 5.45 W, as shown in Figure 5a.…”

Evolution of optical nonlinearity within a graphene/Bi2Te3 heterostructure

“…Through a wide intensity range transmittance measurement, the absorption behaviours of graphene/Bi 2 Te 3 heterostructures at optical intensities from 10 to 10 7 W cm −2 were analyzed. 34 To investigate the optical nonlinearity at an ultra-high optical intensity, a z -scan measurement with a low repetition rate pulsed laser was undertaken. Fig.…”

“…The results in ref. 34 and Fig. 5 show that the heterostructure preserves the individual material properties; however, the optical nonlinearity changes significantly owing to carrier-transfer that was caused by the p–n junction.…”

“…Finally, the as-prepared layer graphene was transferred by chemical vapor deposition (CVD) onto a Bi 2 Te 3 nanoplate. 34,39…”

Multiple-Dimensionally Controllable Nucleation Sites of Two-Dimensional WS2/Bi2Se3 Heterojunctions Based on Vapor Growth

“…CVD-grown (chemical vapor deposition) atomic-scale two-dimensional (2D) heterostructures are of great interest in extensive applications in transistors, diodes, and photodetectors due to their excellent optoelectronic properties. − Considerable 2D heterostructures, such as graphene/TMDs (transition-metal sulfides), − graphene/TI (topological insulators), − TMDs/TI, − and TMDs/TMDs, − have been synthesized by CVD in past few years. However, the precise control of nucleation is still a significant challenge during the CVD process.…”