Electroreflectance of gallium arsenide

"The electroreflectance spectrum of n-type gallium arsenide in the 1.2 - 5.3 eV photon energy range has been measured. The 6e l and 6e2 l1neshapes of six different critical points were analyzed in detail by fitting the one-electron Frapz-Keldysh-Aspnes theory to each separate critical point structure observed. The Eo critical ~oint energy was determined to be 1.427 ± .003eV (at OOC), the spin orbit splitting 60 =.331;> ± .013 eV. The interference between the light and heavy hole transitions at Eo has been -""-----""-~- observed and the reduced effective masses determined to be: light hole reduced effective mass iJ..e"",,::.030,± .005 me' he~vy hole reduced mass iJ.h = .062 ± .015 me' The next higher energy structures,El, El+Al~ were found to be best represented by two-dimensional critical point theory. These structures are attributed to transitions all along a critical line extending 70% of the way along A from L towards r. The El energy was determined to be 2.884 ± .012 eV (at OOC) and the spin orbit splitting ~\ = .2'1-7 :!: .010 aV. Two structures were seen in the 4.0 - 5.3 eV photon energy range. The first of these, E', haS more oscillations than have been previous1y reported in electroreflectance work on this structure, but remains poorly understood. The second structure, E Z' is compatible with a one-dimensional critical point theory but 1s so broad that it also fits other possibilities. The one-dimensional theory places the critical point energy at E2 = 4.951 ± .020 eV (at OOC) and indicates that the critical plateaux responsible 'have a total effective area of .18 (l/a!) per Brillouin zone. In addition to these results lineshapes for flatband-to-accumulation modulations of the space charge electric field which may be due to band-filling at r, the low point of the conduction banels, have been observed. Finally, electroreflectance lineshapes which can be 9learly identified as field derivatives of Ae are reported for the first time."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2012

Author dc:creator

• Pond, Stephen Fullerton

• Gallium Arsenide (GaAs)
• electroreflectance

Statement dc:rights

• © Stephen Fullerton Pond

Language dc:language

en

Identifier

5323621

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/29948