Selective sensing of terahertz (THz) radiation by beryllium and silicon delta-doped GaAs/AlAs multiple quantum wells (MQWs) is demonstrated. A sensitivity up to 0.3 V/W within 0.5{4.2 THz in silicon- and up to 1 V/W within 4.2-7.3 THz range in beryllium-doped MQWs at liquid helium temperatures is shown. The built-in electric fields as estimated from the observed Franz-Keldysh oscillations in photoreflectance spectra were found to be located close to the cap and buffer layers of MQWs and vary from 18 kV/cm up to 49 kV/cm depending on the structure design.
@article{arxiv.0711.0460,
title = {Terahertz sensing by beryllium and silicon delta-doped GaAs/AlAs quantum wells},
author = {D. Seliuta and J. Kavaliauskas and B. Cechavicius and S. Balakauskas and G. Valusis and B. Sherliker and M. P. Halsall and P. Harrison and M. Lachab and S. P. Khanna and E. H. Linfield},
journal= {arXiv preprint arXiv:0711.0460},
year = {2007}
}