Abstract
The effect of thermal treatment and annealing under different temperatures from 100 °C to 250 °C on the photoluminescence spectroscopy of the GeSe ultrathin slab is reported. After the thermal treatment and annealing under 200 °C, we found that the photoluminescence intensity of A exciton and B exciton in GeSe ultrathin slab is increased to twice as much as that in untreated case, while is increased by ~84% in the photoluminescence intensity of C exciton. Combined by our experimental work and theoretical simulations, our study confirms the significant role of thermal treatments and annealing in reducing surface roughness and removing the Se vacancy to form more compact and smoother regions in GeSe ultrathin slab. Our findings imply that the improved quality of GeSe surface after thermal treatments is an important factor for the photoluminescence enhancement.
Highlights
In recent years, two-dimensional (2D) semiconductor materials have become the research focus of nanoscience due to their interesting physical properties[1,2,3,4]
In order to confirm the effect of thermal annealing on the roughness, we measured the roughness of the thinned germanium selenide (GeSe) ultrathin slab before and after the annealing at various spots of the samples
Ra reaches a minimum value of 1.952 nm after the thermal annealing under 200 °C. It means that the smoothness of the GeSe surface of the thinned areas is increased by thermal treatment and annealing under this temperature
Summary
Two-dimensional (2D) semiconductor materials have become the research focus of nanoscience due to their interesting physical properties[1,2,3,4]. To improve the quantum efficiency of PL15–17, high temperature annealing method was used to optimize the structure of ultra-thin MoS2 film, which effectively increases the mobility of carriers and reduces the defects on its surface[18]. We previously reported that the quantum efficiency of MoS2 ultrathin slab under thermal treatments can be increased twice of that under room temperature (RT)[20]. The mechanism of the thermal treatments under different annealing temperature on the PL intensity of GeSe ultrathin slab is still a challenge issue. Combined by our experimental work and theoretical simulations, our study confirms the significant role of thermal treatments and annealing in reducing surface roughness and removing the Se vacancy to form more compact and smoother regions in GeSe ultrathin slab. Our findings imply that the improvement of the surface smoothness in GeSe samples is an important factor for PL enhancement after thermal treatments
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
