OBSERVATION OF A METASTABLE DEFECT TRANSITION IN GAAS

We show that the well-known 0.15-eV donor in bulk GaAs quenches under IR-light illumination and that the quenched (metastable) state has an electronic transition energy about 0.14 eV deeper than the ground stat e and can be observed by temperature-dependent-resistivity and Hall-ef fect measurements. The quenched state thermally recovers by an Auger-l ike process at a rate of r = 2.3X10(-12) nv(n) exp(-0.18/kT). Many of the properties exhibited by this donor are similar to those predicted theoretically for the complex defect As(Ga)-V(As).