Optoelectronic characteristics of CdTe/HgTe/CdTe quantum-dot quantum-well (QDQW) nanoparticles synthesized by the colloidal method are investigated in this study. Strong exciton bands were observed in absorption and photoluminescence (PL) spectra taken for the CdTe/HgTe/CdTe QDQW nanoparticles. The energy difference between the exciton absorption and PL bands is larger than those obtained with CdTe and HgTe nanoparticles. Photocurrent-voltage curves and time-dependent photocurrent curves were obtained for the CdTe/HgTe/CdTe QDQW nanoparticles. With regard to the photocurrent mechanism of these QDQW nanoparticles, those charge carriers participating in the formation of excitons may not contribute to the photocurrent, because of the large binding energy of the excitons. Moreover, it is suggested in this paper that free holes in the HgTe quantum-well in the valance band, rather than free electrons, are the main contributors to the photocurrent.
Bibliographical noteFunding Information:
This study was supported by the National Research Program for 0.1 Terabit Non-Volatile Memory Development (10022965-2005-11), the National Research Laboratory (M10500000045-05J0000-04510), the National R&D Project for Nano Science and Technology (10022916-2005-21), and the Center for Integrated-Nano-Systems (CINS) of the Korea Research Foundation (KRF-2005-005-D00087).
- A. CdTe/HgTe/CdTe nanoparticles
- A. Quantum-dot quantum-well
- D. Optical properties
- D. Photocurrent
ASJC Scopus subject areas
- Condensed Matter Physics
- Materials Chemistry