Sulfur Passivation of GaAsSb alloy layer Surfaces: Comparison of Ammonium Sulfide and Disulfur Dichloride Solutions

摘要

In this paper, (NH_4)_2S and S2Cl2 are used as passivating agent for the sulphuration treatment to GaAs0.03Sb0.97. The effect of surface passivation of GaAs0.03Sb0.97 by (NH_4)_2S and S2Cl2 treatment is investigated by using photoluminescence (PL), Atomic Force Microscope (AFM). Compared with the pristine sample, the PL intensities of GaAs0.03Sb0.97 that treated by (NH_4)_2S and S2Cl2 both are increased significantly. The PL intensity is strongly dependent on passivation time. For the 10s S2Cl2-treated sample, the peak intensity is about 1.4 times larger than 20 min (NH_4)_2S-treated sample. Meanwhile, AFM images indicate that the roughness of the S2Cl2 treated sample is smaller than the (NH_4)_2S treated sample. Thus, S2Cl2 passivation is an effective method in improving the optical properties of GaAs0.03Sb0.97 material.