Burstein-Moss shift ofn-dopedIn0.53Ga0.47As/

Abstract

We have evaluated the Burstein-Moss ͑BM͒ shift at 300 K in seven samples of n-In 0.53 Ga 0.47 As (1.3 ϫ10 16 рnр3.9ϫ10 19 cm Ϫ3 ) lattice matched to InP using spectral ellipsometry in the range of 0.4-5.1 eV. The data have been fitted over the entire spectral range to a model reported by Holden et al. ͓in Thermphotovoltaic Generation of Electricity, edited by T. J. Coutts, J. P. Brenner, and C. S. Allman, AIP Conf. Proc. No. 460 ͑AIP, Woodbury, NY, 1999͒, p. 39͔, based on the electronic energy-band structure near critical points plus relevant discrete and continuum excitonic effects. A Fermi-level filling factor in the region of the fundamental gap has been used to account for the BM effect. While our data exhibit nonparabolic effects, with a blueshift of 415 meV for the most highly doped sample, we did not observe the Fermi-level saturation at 130 meV for nу10 19 cm Ϫ3 reported by Tsukernik et al. . Our BM displacements are in agreement with a modified full-potential linearized augmented-plane-wave calculation ͓G. W. Charache et al., J. Appl. Phys. 86, 452 ͑1999͔͒ plus possible band-gap-reduction effects.The study of the Burstein-Moss ͑BM͒ effect in n-In 0.53 Ga 0.47 As lattice matched to InP is important from both fundamental and applied points of view. Recently Tsukernik et al. 1 presented an investigation of the BM shift in this material based on thermionic emission and diffusion over a barrier and concluded that the BM change saturates at about 130 meV for nу10 19 cm Ϫ3 . This observation was explained as a ''Fermi-level saturation;'' based on their results the authors called for a reexamination of existing theories. In contrast, Charache et al. 2 and Holden et al. 3 did not observe such a Fermi-level saturation in heavily doped n-In 0.66 Ga 0.34 As. Structures based on highly n-doped In 0.53 Ga 0.47 As materials have been used for several kinds of semiconductor devices such as heterojunction bipolar transistors, 4 resonant-tunneling devices, 5 and Bragg reflectors for surface-emitting lasers. 6 For these kinds of applications it is highly desirable to have information about the position of the Fermi level relative to the conduction-band edge.We present a study of the BM effect at 300 K in seven samples of n-In 0.53 Ga 0.47 As (1.3ϫ10 16 рnр3.9ϫ10 19 cm Ϫ3 ) lattice matched to InP using spectral ellipsometry. The data have been fitted using a comprehensive model 3,7 based on the electronic energy-band structure near critical points plus relevant discrete and continuum excitonic effects. The BM shift at the direct gap was accounted for using a Fermi-level filling factor in addition to the discrete and continuum excitonic terms. 3 The Fermi-level alteration exhibits nonparabolic effects. However, in contrast to Ref. 1, we did not observe a Fermi-level saturation. Our results exhibit a blueshift of 415 meV for the highest doped sample (nϭ3.9 ϫ10 19 cm Ϫ3 ). The BM displacements of this work are in agreement with a modified full-potential linearized augmented-plane-wave ͑FLAPW͒ calculation 2 plus possible band-...

LP-MOVPE growth and properties of high Si-doped InGaAs contact layer for quantum cascade laser applications

“…Obtained values of DE g are lower than theoreti− cal calculations and discrepancy rises with the doping concen− tration to 80 meV for n = 4×10 18 cm -3 and about 237 meV for the highest electron concentration achieved in this work (2.8×10 20 cm -3 ). Such differences between experimental re− sults and theoretical predictions of the bandgap shift of hea− vily doped semiconductors were also reported by other au− thors [17,18] what confirms the need of experimental works in this field to improve the existing theoretical models.…”

Optical Properties of ZnO:Al Epilayers and of Undoped Epilayers Capped by Wider-Gap MgZnO Grown by Laser MBE

“…This indicating that these spectra should be interpreted in the framework of BursteinMoss (BM) effect. These data have been fitted using a comprehensive model based on the electronic energy-band structure near the optical band gap with excitonic effects [5]. In the fundamental absorption region, the BM shift has been taken into account by the introduction of a Fermi-level filling factor (FLFF).…”

Optical properties of Cl-doped ZnSe epilayers grown on GaAs substrates

“…In fact, for some semiconductor systems, theoretical work suggests that the electronelectron interactions are proportional to n 1/3 , while the electron-ion interactions are proportional to n 1/2 . 17 We are in the process of pursuing similar calculations for the ZnSe system in order to verify these effects. In this paper, we concentrate only on the Burstein-Moss effect, and Fig.…”

“…As a result, the fundamental transition is blue shifted compared to the transition in the undoped semiconductor. This is known as the Burstein-Moss effect, 13,14 in the literature, and has been carefully studied in several III-V semiconductors, including GaAs, 2,15 InP, 16 InGaAs, 17 and InGaP. 18 Additionally, there are two other effects that tend to cause the band gap to red shift due to doping in a semiconductor.…”

“…One could account for the Burstein-Moss effect plus the other two band gap reducing effects using the following: 17 where m* is the effective mass of the electron, and the n is the carrier concentration in the semiconductor. While the first expression in the above equation describes the energy band enlargement due to the Burstein-Moss effect, the second parameter (E BGR ) accounts for the deflation of the energy band due to electron-electron and electron-ion interactions.…”