LAUSR

The variation of the effective lifetime of minority carrier lifetime τeff with temperature has been studied in the temperature range 300–580 K in AlxGa1−xAs base regions of p+–p0–i–n0–n+ high-voltage GaAs–AlGaAs diodes grown by liquid-phase epitaxy. It was found by using deep level transient spectroscopy that the emission/capture of electrons and holes in AlxGa1−xAs p0–i–n0 epitaxial layers is governed by the DX− states of the DX center formed by Se/Te background impurities. The Arrhenius plots associated with the τeff were used to determine the activation energy of the hole capture to the DX− level to be Ec = 159 meV. It is shown that the thermal capture of holes to the DX− level determines the relaxation time of nonequilibrium carriers in the AlxGa1−xAs base layers as well as its temperature dependence.