It was pointed out here that the Te donor formed a deep level and acted as a DX center in InGaAsP/GaAs0.61P0.39. The characteristics of the Te-related deep level were investigated by means of deep-level transient spectroscopy and thermally stimulated capacitance measurements. It was found that the deep level had a thermal activation energy of 0.14eV; regardless of the composition of the InGaAsP. A persistent photoconductivity was observed at low temperatures in all of the Te-doped samples. The compositional dependence of the deep-trap density was explained in terms of the energy difference between the conduction band minimum and the DX level.

B.D.Jeon, H.K.Kwon, B.D.Choe: Applied Physics Letters, 1996, 69[19], 2912-4