2026-09-21T13:18:35Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/25692 2023-07-10 col_2142_8859 col_2142_5131 com_2142_8858 com_2142_234 com_2142_5130

Handler, Paul Germano, Francisco Alcides 2011-07-07T16:05:16Z 2011-07-07T16:05:16Z 10000-01-01 1967 The effect of an electric field on the optical absorption near the fundamental edge of germanium was measured, employing a-c electroabsorption techniques, from 14 to 3000K with electric fields varying from 5 x 103 V/cm to 5 x 104 V/cm. The curves of the fieldinduced differential absorption coefficient Aa exhibit oscillations which, in the case of the direct edge spectrum, are satellite oscillations related to the Franz-Keldysh leffect dear a M edge, o modified by excitonic effects; in the case of the indirect edge they are due to the electric-field-induced change in the optical absorption assisted by phonon emission and absorption. The electric field dependence of the width of the oscillations in 6a above the direct energy gap agrees with the theory derived from an effective mass approximation. Analysis of the data below the gap resulted in an effective mass of 0.022 m at room temperature and 0.024 m at the lower temperatures. The amplitude of 6a is very sensitive to the temperature, while the shape of the spectrum is almost temperature independent. From the data near the indirect edge at room temperature, the energies of the phonons which take part in the indirect absorption are determined. The effects of the longitudinal acoustical (27.7 meV) and transversal acoustical (7.3 meV) phonons are predominant. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-07-07T16:05:15Z No. of bitstreams: 1 1967_germano.pdf: 4243985 bytes, checksum: 962433bba84f1f93555b80531ab304d3 (MD5) Made available in DSpace on 2011-07-07T16:05:16Z (GMT). No. of bitstreams: 1 1967_germano.pdf: 4243985 bytes, checksum: 962433bba84f1f93555b80531ab304d3 (MD5) Previous issue date: 1967 Restriction data tranferred 2014-07-01T11:32:44-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-07-07T16:05:16Z Item is restricted indefinitely. Thesis U of I Only 6087779 http://hdl.handle.net/2142/25692 en 1967 Francisco Alcides Germano electroabsorption germanium optical absorption fundamental edges of germanium phonon emission Electroabsorption effects near the direct and indirect edges of germanium Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.