We present intersubband absorption in the conduction band of compressively strained germanium quantum wells bounded by Ge-rich SiGe barriers. The measured absorption energies are in the 5-12 THz range depending on the well width. These results may be relevant for the design of SiGe-based THz Quantum Cascade emitters.
Busby, Y., Capellini, G., Evangelisti, F., Ortolani, M., Virgilio, M., Grosso, G., et al. (2010). Terahertz intersubband transitions in the conduction band of Ge/SiGe multi quantum wells. In Proceedings of 35th International Conference on Infrared Millimeter and Terahertz Waves (IRMMW-THz) [10.1109/ICIMW.2010.5612749].