Abstract

Towards the realization of both detectors and emitters operating in the THz, semiconductor nanostructures, such as quantum wells (QW) and quantum dots (QD) have drawn a lot of attention. On the other hand, the intentionally doped impurities in semiconductors have also energy separations in the THz region and their radiative transitions are dipole allowed. Therefore, an alternative approach using hydrogen like energy levels of the shallow impurities in quantum wells has been proposed for both THz generation and detection (Figure 1). The binding energies of the ground (1s-like) and excited (2p-like) states of an impurity associated with the first subband in a quantum well depend on the quantum well width, position of the impurity in the well, as well as the type of the impurity. With these tuning capabilities, it is possible to cover a broad range of THz spectrum.

© 2014 Optical Society of America