We have investigated the room temperature deposition of ultrathin bismuth layers on GaAs(110) surfaces by using Surface Differential Reflectance (SDR) spectroscopy. In SDR spectra measured at the "as grown" surfaces, optical transitions related to the new electronic structure of the overlayer appear at 0.8 eV and 1.35 eV, below the gap of bulk gallium arsenide. Because of their energy position and dependence upon deposited Bi thickness, we interpret them as related to Bi-overlayer and Bi-substrate bonds, respectively. Subsequent annealings of the overlayer at temperatures in the range 200-350 degrees C have not produced any improvement in the quality of the interface, but a new tweak) transition at about 1.1 eV possibly related to Bi crystallites present at the surface. Annealing at T > 350 degrees C produces desorption of the adsorbed bismuth.
Chiaradia, P., Goletti, C., Jian, W. (1998). Optical properties of bismuth-terminated GaAs(110) surfaces. NUOVO CIMENTO DELLA SOCIETÀ ITALIANA DI FISICA. D CONDENSED MATTER, ATOMIC, MOLECULAR AND CHEMICAL PHYSICS, BIOPHYSICS, 20(7-8), 975-980 [10.1007/BF03185501].
Optical properties of bismuth-terminated GaAs(110) surfaces
CHIARADIA, PIETRO;GOLETTI, CLAUDIO;
1998-01-01
Abstract
We have investigated the room temperature deposition of ultrathin bismuth layers on GaAs(110) surfaces by using Surface Differential Reflectance (SDR) spectroscopy. In SDR spectra measured at the "as grown" surfaces, optical transitions related to the new electronic structure of the overlayer appear at 0.8 eV and 1.35 eV, below the gap of bulk gallium arsenide. Because of their energy position and dependence upon deposited Bi thickness, we interpret them as related to Bi-overlayer and Bi-substrate bonds, respectively. Subsequent annealings of the overlayer at temperatures in the range 200-350 degrees C have not produced any improvement in the quality of the interface, but a new tweak) transition at about 1.1 eV possibly related to Bi crystallites present at the surface. Annealing at T > 350 degrees C produces desorption of the adsorbed bismuth.Questo articolo è pubblicato sotto una Licenza Licenza Creative Commons
