Surface, interface and bulk properties of GaAs(111)B treated by Se layers

The surface and bulk properties of GaAs(111)B with Se surface layers of dif ferent thicknesses have been studied. Insight into the mechanism of this ty pe of surface treatment has been provided by surface-sensitive photoemissio n spectroscopy. It has been found that Se deposited at room temperature on an As rich GaAs(111)B surface initially reacts with As followed by the form ation of a Se overlayer. A relatively large spectral component due to Se-As bond emission was observed. The experimental results show that the Ga and As core levels shift around 0.27 eV after an initial Se deposition, and no additional shift was observed after further Se deposition.