The effects of staggered bandgap in the InP/CdSe and CdSe/InP core/shell quantum dots.
New type-II structures of CdSe/InP and InP/CdSe core-shell nanocrystals which have staggered bandgap alignment were fabricated. Using a simple model for the wave function for electrons and holes in InP/CdSe and CdSe/InP core/shell nanocrystals showed the wave function of the electron and hole spread into the shell, respectively. The probability density of the InP/CdSe and CdSe/InP core/shell QDs also showed a similar tendency. As a result, the structure exhibits increased delocalization of electrons and holes, leading to a red-shift in absorption and emission. Quantum yield increased in the InP/CdSe, however decreased in the CdSe/InP. The reason may be due to the surface trap and high activation barrier for de-trapping in the InP shell.
Kim
Sunghoon
S
Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Republic of Korea.
Park
Jaehyun
J
Kim
Sungwoo
S
Jung
Won
W
Sung
Jaeyoung
J
Kim
Sang-Wook
SW