The hole transport through the minibands of symmetrically strained GexSi1-x/Si superlattices is observed. The superlattices are grown on unstrained Ge x 2Si1- x 2/Si buffer layers. Two peaks are observed from the current-voltage (I-V) and conductance-voltage (dI/dV) measurements, which are due to conduction of light holes through minibands in the superlattice. The second peak shows a negative differential resistance (NDR) region below 100 K. The energies of the minibands are estimated by thermionic emission analysis of current-voltage-temperature (I-V-T) data. Also, we have studied the long wavelength (10 μm) infrared absorption of these superlattice samples by photocurrent measurement. The measured photocurrent as a function of bias shows characteristics similar to the I-V characteristics. The preliminary data on polarization dependence of the photocurrent suggest that the infrared absorption occurs between lighth hole minibands.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry