Far IR impurity photoconductivity in strained MQW Ge/GeSi heterostructures

摘要

Far infrared photocondoctivity ( lambda chemical bounds 100-600 3muE m) in strained MQW Ge/GE_(1-x)Si_x heterostructures was investigated for the first time. In both boron-doped and undoped quantum wells spectral features associated with confined acceptors were revealed. In the undoped sample the broad ong wavelength photoconductivity band associated with shallow A~+ states in quantum wells was discovered in additions to the residual neutral acceptor A~o photoconductivity. In the magnetic fields the photoconductivity band is tuned to the high frequency region. The peak sensitivity o f the impurity photoresistor is estimated to be S chemical bounds 10~4 V/W.