Stark shift of the spectral response in quantum dots-in-a-well infrared photodetectors

We present experimental and theoretical investigations of the bias-dependent spectral shift of the photoresponse in InAs/In_xGa _1-xAs quantum-dots-in-a-well structures. Experimental results show that the wavelength response of the transition from the quantum dot ground state to quantum well states can be Stark-shifted by ∼15% by changing the applied bias between -1 V and +1 V. A theoretical model based on the 8-band k p method fits our experimental data well using realistic dot parameters. We also demonstrate an increase in the operating wavelength and a reduced bias-dependent spectral shift for samples containing dots formed by depositing less InAs during growth.