Electroreflectance of silicon

The major results of this paper are (i) the first high-field flatband-electroflectance data ever taken on silicon and (ii) an analysis with the one-electron theory that shows that the major portion of the direct edge spectrum is an $M_0^{2D}$ from along $\Lambda$ analogous to the $E_1$, $E_1+{\Delta }_1$ structures of germanium and gallium arsenide. The data cover a range of fields from about 77 to 310 kV/cm, and contains more highly resolved structure than any previously reported results. Specifically, the second, weaker transition at the direct edge has been resolved quite clearly. It is shown that this structure may best be fit with an $M_1$ line shape, a result both interesting and controversial. A fundamental band parameter has been determined for the first time from the analysis. The transverse mass along $\Lambda$, ${\mu }_t$, has been found to be $0.02m$, in conflict with all present calculated values. This result is independent of the model used. In addition, we have obtained values for the energy gaps of the two direct-edge structures and an upper bound has been determined for the matrix element of the $\Lambda$ transition.