Influence of the Electric Field on the Exciton Absorption in Germanium

✍ Scribed by A. G. Aronov; I. V. Mochan; V. I. Zemskii

• Publisher: John Wiley and Sons
• Year: 1971
• Tongue: English
• Weight: 518 KB
• Volume: 45
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2220450203

✦ Synopsis

Abstract

In germanium the electro‐absorption in the indirect absorption region was measured by two differential methods: the method of frequency modulation and the method of electro‐modulation. The experimental results are compared to calculations taking the electron–hole interaction into account. A quantitative description of the electro‐absorption spectra is obtained both for the allowed and for the forbidden transitions. It is shown that the first maximum of the electro‐absorption spectrum corresponds to the threshold energy in the case of allowed transitions (if no broadening effects are taken into account), whereas for the forbidden transitions the zero‐point corresponds to the threshold energy. The Franz‐Keldysh effect was also observed in the region of transitions to the continuous spectrum. This effect is found to be considerably smaller than the effects leading to the change of the absorption coefficient by the electric field in the region of transitions to the exciton band.