First results on GaAs blocked impurity band (BIB) structures for far-infrared detector arrays

We are developing a GaAs photoconductive detector for far-infrared (FIR) astronomy. A detector based on GaAs in the blocked impurity band (BIB) con.guration is expected to extend the long wavelegth limit of currently available stressed Ge:Ga photoconductors up to about 330 microns. Without the need of uniaxial stress applied to the crystal, this would furthermore allow the fabrication of single chip arrays with a large number of pixels. We are reporting results of the characterization of preliminary GaAs BIB test structures. The experimental work is supported by numerical modeling that includes all contact and space charge effects.