Linear strain-gradient effect on the energy bandgap in bent CdS nanowires
- 360 Downloads
Although possible non-homogeneous strain effects in semiconductors have been investigated for over a half century and the strain-gradient can be over 1% per micrometer in flexible nanostructures, we still lack an understanding of their influence on energy bands. Here we conduct a systematic cathodoluminescence spectroscopy study of the strain-gradient induced exciton energy shift in elastically curved CdS nanowires at low temperature, and find that the red-shift of the exciton energy in the curved nanowires is proportional to the strain-gradient, an index of lattice distortion. Density functional calculations show the same trend of band gap reduction in curved nanostructures and reveal the underlying mechanism. The significant linear strain-gradient effect on the band gap of semiconductors should shed new light on ways to tune optical-electronic properties in nanoelectronics.
KeywordsStrain-gradient effect CdS nanowire bending deformation cathodoluminescence
Unable to display preview. Download preview PDF.
12274_2010_85_MOESM1_ESM.pdf (797 kb)
- Cao, J.; Ertekin, E.; Srinivasan, V.; Fan, W.; Huang, S.; Zheng, H.; Yim, J. W. L.; Khanal, D. R.; Ogletree, D. F.; Grossman, J. C., et al. Strain engineering and one-dimensional organization of metal-insulator domains in single-crystal vanadium dioxide beams. Nat. Nanotechnol. 2009, 4, 732–737.CrossRefGoogle Scholar
- Trauernicht, D. P.; Mysyrowicz, A.; Wolfe, J. P. Strain confinement and thermodynamics of free excitons in a direct-gap semiconductor. Phys. Rev. Lett. 1983, 28, 3590–3592.Google Scholar
© Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2010