In this paper, CuO/TiO_(2) p-n heterojunction was developed as a new surface enhanced Raman scattering(SERS) substrate to magnify Raman signal of 4-mercaptobenzoic acid(4-MBA) molecule. In the heterojunction-molecule ...In this paper, CuO/TiO_(2) p-n heterojunction was developed as a new surface enhanced Raman scattering(SERS) substrate to magnify Raman signal of 4-mercaptobenzoic acid(4-MBA) molecule. In the heterojunction-molecule system, CuO as an “electron capsule” can not only offer more electrons to inject into the surface state energy level of TiO_(2) and consequently bring additional charge transfer, but also improve photogenerated carrier separation efficiency itself due to strong interfacial coupling in the interface of heterojunction, which together boost SERS performance of the heterojunction substrate. As expected,owing to the enhanced charge collection capacity and the improvement of photogenerated carrier separation efficiency derived from internal electric field and strong interface coupling provided in the interface of heterojunction, this substrate exhibits excellent SERS detection sensitivity towards 4-MBA, with a detection limit as low as 1 × 10^(-10)mol/L and an enhancement factor of 8.87 × 10~6.展开更多
We report on a cross-sectional high resolution transmission electron microscope study of lead sulfide nanocrystal quantum dots （NCQDs） dispersed on electron-transparent silicon nanopillars that enables nearly atomic...We report on a cross-sectional high resolution transmission electron microscope study of lead sulfide nanocrystal quantum dots （NCQDs） dispersed on electron-transparent silicon nanopillars that enables nearly atomically-resolved simultaneous imaging of the entire composite： the quantum dot, the interfacial region, and the silicon substrate. Considerable richness in the nanocrystal shape and orientation with respect to the substrate lattice is observed. The average NCQD-substrate separation is found to be significantly smaller than the length of the ligands on the NCQDs. Complementary photoluminescence measurements show that light emission from PbS NCQDs on silicon is effectively quenched which we attribute to intrinsic mechanisms of energy and charge transfer from PbS NCQDs to Si.展开更多
基金supported by National Natural Science Foundation of China (Nos. 21804054, 21773080)Natural Science Foundation of Heilongjiang Province of China for Distinguished Young Scholars (No. JQ2019B002)+1 种基金Excellent Discipline Team Project of Jiamusi University (No. JDXKTD-2019007)Open Project of State Key Laboratory of Supramolecular Structure and Materials (No. sklssm2021026)。
文摘In this paper, CuO/TiO_(2) p-n heterojunction was developed as a new surface enhanced Raman scattering(SERS) substrate to magnify Raman signal of 4-mercaptobenzoic acid(4-MBA) molecule. In the heterojunction-molecule system, CuO as an “electron capsule” can not only offer more electrons to inject into the surface state energy level of TiO_(2) and consequently bring additional charge transfer, but also improve photogenerated carrier separation efficiency itself due to strong interfacial coupling in the interface of heterojunction, which together boost SERS performance of the heterojunction substrate. As expected,owing to the enhanced charge collection capacity and the improvement of photogenerated carrier separation efficiency derived from internal electric field and strong interface coupling provided in the interface of heterojunction, this substrate exhibits excellent SERS detection sensitivity towards 4-MBA, with a detection limit as low as 1 × 10^(-10)mol/L and an enhancement factor of 8.87 × 10~6.
文摘We report on a cross-sectional high resolution transmission electron microscope study of lead sulfide nanocrystal quantum dots （NCQDs） dispersed on electron-transparent silicon nanopillars that enables nearly atomically-resolved simultaneous imaging of the entire composite： the quantum dot, the interfacial region, and the silicon substrate. Considerable richness in the nanocrystal shape and orientation with respect to the substrate lattice is observed. The average NCQD-substrate separation is found to be significantly smaller than the length of the ligands on the NCQDs. Complementary photoluminescence measurements show that light emission from PbS NCQDs on silicon is effectively quenched which we attribute to intrinsic mechanisms of energy and charge transfer from PbS NCQDs to Si.
