Hybrid structures incorporating both III-nitride and transition-metal dichalcogenide (TMD) semiconductors have strong application potential for light harvesting and optoelectronics. Here, we have investigated the properties of hybrid structures based on a ${\mathrm{Mo}\mathrm{Se}}_2$ monolayer coupled to an $\mathrm{In}\mathrm{Ga}\mathrm{N}$ quantum well (QW). The coupling efficiency is controlled by a thin $\mathrm{Ga}\mathrm{N}$ barrier of variable thickness located between them. Time-integrated and time-resolved microphotoluminescence experiments show a quenching of the $\mathrm{In}\mathrm{Ga}\mathrm{N}$ QW exciton emission, which increases with the decrease of the $\mathrm{Ga}\mathrm{N}$ barrier thickness d: the PL intensity is reduced by a factor of three for d = 1 nm as a consequence of carrier transfer to the ${\mathrm{Mo}\mathrm{Se}}_2$ monolayer. This interplay between the two semiconductors is confirmed by time-resolved photoluminescence spectroscopy, highlighting a clear reduction of the QW exciton lifetime in the presence of the monolayer. Interestingly, the coupling between the QW and the TMD monolayer is also demonstrated by measuring optically the excitonic transport properties in the quantum well: the exciton diffusion length decreases in the presence of the ${\mathrm{Mo}\mathrm{Se}}_2$ monolayer. Measuring dependences as a function of temperature highlights the role played by localization effects in the QW. All these results can be effectively interpreted by a type-II band alignment between the $\mathrm{In}\mathrm{Ga}\mathrm{N}$ QW and the ${\mathrm{Mo}\mathrm{Se}}_2$ monolayer and a tunneling process between the two semiconductors.

Close

PrevNext

View figure in article

• Electronic structure
• Excitons
• Optoelectronics
• Surface & interfacial phenomena
• III-V semiconductors
• Monolayer films
• Quantum wells
• Transition metal dichalcogenides