The use of single-layer MoS2 in light emitting devices requires innovative methods to enhance its low photoluminescence （PL） quantum yield. In this work, we report that single-layer MoS2 with a strong PL can be prep...The use of single-layer MoS2 in light emitting devices requires innovative methods to enhance its low photoluminescence （PL） quantum yield. In this work, we report that single-layer MoS2 with a strong PL can be prepared by oxidizing bilayer MoS2 using W-ozone oxidation. We show that as compared to mechanically-exfoliated single-layer MoS2, the PL intensity of the single-layer MoS2 prepared by W-ozone oxidation is enhanced by 20-30 times. We demonstrate that the PL intensity of both neutral excitons and trions （charged excitons） can be greatly enhanced in the oxidized MoS2 samples. These results provide novel insights into the PL enhancement of single-layer MoS2.展开更多
We have recently demonstrated that GaAs nanosheets can be grown by metal-organic chemical vapor deposition （MOCVD）. Here, we investigate these nanosheets by secondary electron scanning electron microscopy （SE-SEM）...We have recently demonstrated that GaAs nanosheets can be grown by metal-organic chemical vapor deposition （MOCVD）. Here, we investigate these nanosheets by secondary electron scanning electron microscopy （SE-SEM） and electron beam induced current （EBIC） imaging. An abrupt boundary is observed between an initial growth region and an overgrowth region in the nanosheets. The SE-SEM contrast between these two regions is attributed to the inversion of doping at the boundary. EBIC mapping reveals a p-n junction formed along the boundary between these two regions. Rectifying I-V behavior is observed across the boundary further indicating the formation of a p-n junction. The electron concentration （ND） of the initial growth region is around 1 × 10^18 cm^-3, as determined by both Hall effect measurements and low temperature photoluminescence （PL） spectroscopy. Based on the EBIC data, the minority carrier diffusion length of the nanosheets is 177 nm, which is substantially longer than the corresponding length in unpassivated GaAs nanowires measured previously.展开更多
O482.31 95032051MOCVD的InGaAs/GaAs应变层量子阱的低温光致发光研究=Studies on low temperature photo-lumineseence spectra of InGaAs/GaAs stra-ined quantum wells by MOCVD[刊,中]/王小军,王启明,庄婉如,郑婉华(中科院半导体所...O482.31 95032051MOCVD的InGaAs/GaAs应变层量子阱的低温光致发光研究=Studies on low temperature photo-lumineseence spectra of InGaAs/GaAs stra-ined quantum wells by MOCVD[刊,中]/王小军,王启明,庄婉如,郑婉华(中科院半导体所集成光电子学国家重点联合实验室.北京(100083))。展开更多
文摘The use of single-layer MoS2 in light emitting devices requires innovative methods to enhance its low photoluminescence （PL） quantum yield. In this work, we report that single-layer MoS2 with a strong PL can be prepared by oxidizing bilayer MoS2 using W-ozone oxidation. We show that as compared to mechanically-exfoliated single-layer MoS2, the PL intensity of the single-layer MoS2 prepared by W-ozone oxidation is enhanced by 20-30 times. We demonstrate that the PL intensity of both neutral excitons and trions （charged excitons） can be greatly enhanced in the oxidized MoS2 samples. These results provide novel insights into the PL enhancement of single-layer MoS2.
文摘We have recently demonstrated that GaAs nanosheets can be grown by metal-organic chemical vapor deposition （MOCVD）. Here, we investigate these nanosheets by secondary electron scanning electron microscopy （SE-SEM） and electron beam induced current （EBIC） imaging. An abrupt boundary is observed between an initial growth region and an overgrowth region in the nanosheets. The SE-SEM contrast between these two regions is attributed to the inversion of doping at the boundary. EBIC mapping reveals a p-n junction formed along the boundary between these two regions. Rectifying I-V behavior is observed across the boundary further indicating the formation of a p-n junction. The electron concentration （ND） of the initial growth region is around 1 × 10^18 cm^-3, as determined by both Hall effect measurements and low temperature photoluminescence （PL） spectroscopy. Based on the EBIC data, the minority carrier diffusion length of the nanosheets is 177 nm, which is substantially longer than the corresponding length in unpassivated GaAs nanowires measured previously.
文摘O482.31 95032051MOCVD的InGaAs/GaAs应变层量子阱的低温光致发光研究=Studies on low temperature photo-lumineseence spectra of InGaAs/GaAs stra-ined quantum wells by MOCVD[刊,中]/王小军,王启明,庄婉如,郑婉华(中科院半导体所集成光电子学国家重点联合实验室.北京(100083))。
