Nanocrystal-semiconductor interface: Atomic-resolution cross-sectional transmission electron microscope study of lead sulfide nanocrystal quantum dots on crystalline silicon

作者：Lingley Zachary; Mahalingam Krishnamurthy; Lu Siyuan; Brown Gail J; Madhukar Anupam^*

来源：Nano Research, 2014, 7(2): 219-227.

DOI：10.1007/s12274-013-0389-4

• nanocrystal quantum dots
• semiconductor substrate
• interface atomic structure
• high resolution transmission electron microscopy
• energy and charge transfer
• solar cells

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.

• 出版日期2014-2