摘要

There are kinds of reconstructions on InGaAs(100) surface, such as As-rich beta(2)(2 x 4), In-rich alpha(2 x 4), and Ga-rich alpha(2 x 4) reconstructions. In this article, the three kinds of In0.53Ga0.47As(100) reconstruction surfaces are studied based on first-principles calculations, and atomic strictures, formation energies, band structures, electron distributions, and absorption coefficients were obtained. Atomic structures of the surfaces were calculated and results show that the relaxation of As-rich beta(2)(2 x 4) surface is the smallest. The As-rich beta(2)(2 x 4) surface also has the smallest formation energy, which means the As-rich beta(2)(2 x 4) surface is the steadiest among the three surfaces. Furthermore, the energy band structures and the work function are analyzed. The less the work function is, the easier the photoelectrons escape from the surfaces. Therefore, it is the easiest for photoelectrons to escape from As-rich beta(2)(2 x 4) surface due to its lowest work function. The same conclusion is also confirmed based on the calculations of the electronic structure. The negative electron affinity photocathode is mainly sensitive to the infrared region where the absorption coefficient of the As-rich beta(2)(2 x 4) surface is bigger than those of the In-rich alpha(2 x 4) and Ga-rich alpha(2 x 4) surfaces. The As-rich 132(2 x 4) surface is benefit for the formation of the negative electron affinity In0.53Ga0.47As photocathode.