Author:
Gallacher Kevin,Ballabio Andrea,Millar Ross,Frigerio Jacopo,Bashir Aneeqa,MacLaren Ian,Isella Giovanni,Ortolani Michele,Paul Douglas J
Abstract
Mid-infrared intersubband absorption from p-Ge quantum wells with Si0.5Ge0.5 barriers grown on a relaxed Si0.2Ge0.8 buffer on a Si substrate is demonstrated from 6 to 9 μm wavelength at room temperature and can be tuned by adjusting the quantum well thickness. Fourier transform infra-red transmission demonstrate clear absorption peaks corresponding to intersubband transitions among confined hole states. The work indicates an approach that will allow quantum well intersubband photodetectors to be realized on Si substrates in the important atmospheric transmission window of 8-13 μm where many chemical and biological molecules have unique molecular absorption lines for spectroscopic identification.
Publisher
The Electrochemical Society