skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Localization landscape theory of disorder in semiconductors. II. Urbach tails of disordered quantum well layers

Abstract

Urbach tails in semiconductors are often associated to effects of compositional disorder. The Urbach tail observed in InGaN alloy quantum wells of solar cells and LEDs by biased photocurrent spectroscopy is shown to be characteristic of the ternary alloy disorder. The broadening of the absorption edge observed for quantum wells emitting from violet to green (indium content ranging from 0% to 28%) corresponds to a typical Urbach energy of 20 meV. A three-dimensional absorption model is developed based on a recent theory of disorder-induced localization which provides the effective potential seen by the localized carriers without having to resort to the solution of the Schrödinger equation in a disordered potential. This model incorporating compositional disorder accounts well for the experimental broadening of the Urbach tail of the absorption edge. For energies below the Urbach tail of the InGaN quantum wells, type-II well-to-barrier transitions are observed and modeled. This contribution to the below-band-gap absorption is particularly efficient in near-ultraviolet emitting quantum wells.When reverse biasing the device, the well-to-barrier below-band-gap absorption exhibits a red-shift, while the Urbach tail corresponding to the absorption within the quantum wells is blue-shifted, due to the partial compensation of the internal piezoelectric fields by the external bias.more » The good agreement between the measured Urbach tail and its modeling by the localization theory thus demonstrates the applicability of the latter to compositional disorder effects in nitride semiconductors.« less

Authors:
 [1];  [2];  [2];  [3];  [3];  [3];  [4];  [4];  [4];  [1]
  1. Ecole Polytechnique, Univ. of Paris-Saclay, Palaiseau (France). Lab. of Condensed Matter Physics; Univ. of California, Santa Barbara, CA (United States). Dept. of Materials
  2. National Taiwan Univ., Taipei (Taiwan). Graduate Inst. of Photonics and Optoelectronics and Dept. of Electrical Engineering
  3. Univ. of California, Santa Barbara, CA (United States). Dept. of Materials
  4. Ecole Polytechnique, Univ. of Paris-Saclay, Palaiseau (France). Lab. of Condensed Matter Physics
Publication Date:
Research Org.:
Univ. of California, Santa Barbara, CA (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B); French National Research Agency (ANR); Ministry of Science and Technology (MOST), Taipei (Taiwan)
OSTI Identifier:
1429092
Alternate Identifier(s):
OSTI ID: 1352104
Grant/Contract Number:  
EE0007096; ANR-14-CE05-0048-01; MOST-104-2923-E-002-004-MY3; MOST-105-2221-E-002-098-MY3
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 95; Journal Issue: 14; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 14 SOLAR ENERGY; 36 MATERIALS SCIENCE; disordered alloys; LEDs; nitrides; semiconductor compounds; optical absorption spectroscopy

Citation Formats

Piccardo, Marco, Li, Chi-Kang, Wu, Yuh-Renn, Speck, James S., Bonef, Bastien, Farrell, Robert M., Filoche, Marcel, Martinelli, Lucio, Peretti, Jacques, and Weisbuch, Claude. Localization landscape theory of disorder in semiconductors. II. Urbach tails of disordered quantum well layers. United States: N. p., 2017. Web. doi:10.1103/physrevb.95.144205.
Piccardo, Marco, Li, Chi-Kang, Wu, Yuh-Renn, Speck, James S., Bonef, Bastien, Farrell, Robert M., Filoche, Marcel, Martinelli, Lucio, Peretti, Jacques, & Weisbuch, Claude. Localization landscape theory of disorder in semiconductors. II. Urbach tails of disordered quantum well layers. United States. doi:10.1103/physrevb.95.144205.
Piccardo, Marco, Li, Chi-Kang, Wu, Yuh-Renn, Speck, James S., Bonef, Bastien, Farrell, Robert M., Filoche, Marcel, Martinelli, Lucio, Peretti, Jacques, and Weisbuch, Claude. Tue . "Localization landscape theory of disorder in semiconductors. II. Urbach tails of disordered quantum well layers". United States. doi:10.1103/physrevb.95.144205. https://www.osti.gov/servlets/purl/1429092.
@article{osti_1429092,
title = {Localization landscape theory of disorder in semiconductors. II. Urbach tails of disordered quantum well layers},
author = {Piccardo, Marco and Li, Chi-Kang and Wu, Yuh-Renn and Speck, James S. and Bonef, Bastien and Farrell, Robert M. and Filoche, Marcel and Martinelli, Lucio and Peretti, Jacques and Weisbuch, Claude},
abstractNote = {Urbach tails in semiconductors are often associated to effects of compositional disorder. The Urbach tail observed in InGaN alloy quantum wells of solar cells and LEDs by biased photocurrent spectroscopy is shown to be characteristic of the ternary alloy disorder. The broadening of the absorption edge observed for quantum wells emitting from violet to green (indium content ranging from 0% to 28%) corresponds to a typical Urbach energy of 20 meV. A three-dimensional absorption model is developed based on a recent theory of disorder-induced localization which provides the effective potential seen by the localized carriers without having to resort to the solution of the Schrödinger equation in a disordered potential. This model incorporating compositional disorder accounts well for the experimental broadening of the Urbach tail of the absorption edge. For energies below the Urbach tail of the InGaN quantum wells, type-II well-to-barrier transitions are observed and modeled. This contribution to the below-band-gap absorption is particularly efficient in near-ultraviolet emitting quantum wells.When reverse biasing the device, the well-to-barrier below-band-gap absorption exhibits a red-shift, while the Urbach tail corresponding to the absorption within the quantum wells is blue-shifted, due to the partial compensation of the internal piezoelectric fields by the external bias. The good agreement between the measured Urbach tail and its modeling by the localization theory thus demonstrates the applicability of the latter to compositional disorder effects in nitride semiconductors.},
doi = {10.1103/physrevb.95.144205},
journal = {Physical Review B},
number = 14,
volume = 95,
place = {United States},
year = {2017},
month = {4}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 7 works
Citation information provided by
Web of Science

Figures / Tables:

FIG. 1 FIG. 1: (a) Schematic of the InGaN/GaN solar cell structures grown by MOCVD. (b) Contact geometry of the processed devices.

Save / Share:

Works referenced in this record:

The Long-Wavelength Edge of Photographic Sensitivity and of the Electronic Absorption of Solids
journal, December 1953


Universal mechanism for Anderson and weak localization
journal, August 2012

  • Filoche, M.; Mayboroda, S.
  • Proceedings of the National Academy of Sciences, Vol. 109, Issue 37
  • DOI: 10.1073/pnas.1120432109

Bandgap determination based on electrical quantum efficiency
journal, July 2013

  • Helmers, Henning; Karcher, Christian; Bett, Andreas W.
  • Applied Physics Letters, Vol. 103, Issue 3
  • DOI: 10.1063/1.4816079

Localization landscape theory of disorder in semiconductors. I. Theory and modeling
journal, April 2017


Atomistic analysis of the impact of alloy and well-width fluctuations on the electronic and optical properties of InGaN/GaN quantum wells
journal, January 2015


Temperature- and Bias-dependent Study of Photocurrent Spectroscopy in an InGaN Light-emitting Diode Operating near 400 nm
journal, October 2010

  • Yee, Kiju; Kim, C. S.; Kim, J. H.
  • Journal of the Korean Physical Society, Vol. 57, Issue 4
  • DOI: 10.3938/jkps.57.793

Probing Individual Localization Centers in an InGaN / GaN Quantum Well
journal, March 2004


The influence of random indium alloy fluctuations in indium gallium nitride quantum wells on the device behavior
journal, September 2014

  • Yang, Tsung-Jui; Shivaraman, Ravi; Speck, James S.
  • Journal of Applied Physics, Vol. 116, Issue 11
  • DOI: 10.1063/1.4896103

“S-shaped” temperature-dependent emission shift and carrier dynamics in InGaN/GaN multiple quantum wells
journal, September 1998

  • Cho, Yong-Hoon; Gainer, G. H.; Fischer, A. J.
  • Applied Physics Letters, Vol. 73, Issue 10
  • DOI: 10.1063/1.122164

Effective Confining Potential of Quantum States in Disordered Media
journal, February 2016


Alloying induced degradation of the absorption edge of InAsxSb1−x
journal, March 2007

  • Bansal, Bhavtosh; Dixit, V. K.; Venkataraman, V.
  • Applied Physics Letters, Vol. 90, Issue 10
  • DOI: 10.1063/1.2711388

Theory of Electron Band Tails and the Urbach Optical-Absorption Edge
journal, October 1986


Absorption spectra of GaN: film characterization by Urbach spectral tail and the effect of electric field
journal, September 2001


Quantum-corrected drift-diffusion models for transport in semiconductor devices
journal, April 2005

  • de Falco, Carlo; Gatti, Emilio; Lacaita, Andrea L.
  • Journal of Computational Physics, Vol. 204, Issue 2
  • DOI: 10.1016/j.jcp.2004.10.029

The optical and structural properties of InGaN epilayers with very high indium content
journal, May 1999


Urbach rule
journal, November 1971


Origin of Luminescence from InGaN Diodes
journal, January 1999


Disorder and the Optical-Absorption Edge of Hydrogenated Amorphous Silicon
journal, November 1981


Bias dependent spatially resolved photoluminescence spectroscopy and photocurrent measurements of InGaN/GaN LED structures
journal, January 2009

  • Vierheilig, Clemens; Schwarz, Ulrich T.; Gmeinwieser, Nikolaus
  • physica status solidi (c), Vol. 6, Issue S2
  • DOI: 10.1002/pssc.200880881

Band parameters for III–V compound semiconductors and their alloys
journal, June 2001

  • Vurgaftman, I.; Meyer, J. R.; Ram-Mohan, L. R.
  • Journal of Applied Physics, Vol. 89, Issue 11, p. 5815-5875
  • DOI: 10.1063/1.1368156

Enhancement of Auger recombination induced by carrier localization in InGaN/GaN quantum wells
journal, March 2017


Investigation of nanoscale composition fluctuations in InGaN using optical transmission spectroscopy and near-field scanning optical microscopy
journal, April 2006

  • Han, B.; Wessels, B. W.; Ulmer, M. P.
  • Journal of Applied Physics, Vol. 99, Issue 8
  • DOI: 10.1063/1.2189019

Percolation transport study in nitride based LED by considering the random alloy fluctuation
journal, March 2015

  • Wu, Chen-Kuo; Li, Chi-Kang; Wu, Yuh-Renn
  • Journal of Computational Electronics, Vol. 14, Issue 2
  • DOI: 10.1007/s10825-015-0688-y

First-principles calculations of indirect Auger recombination in nitride semiconductors
journal, July 2015


Toward a Unified Theory of Urbach's Rule and Exponential Absorption Edges
journal, January 1972


Carrier escape mechanism dependence on barrier thickness and temperature in InGaN quantum well solar cells
journal, October 2012

  • Lang, J. R.; Young, N. G.; Farrell, R. M.
  • Applied Physics Letters, Vol. 101, Issue 18
  • DOI: 10.1063/1.4765068

Urbach–Martienssen tails in a wurtzite GaN epilayer
journal, June 1997

  • Chichibu, S.; Mizutani, T.; Shioda, T.
  • Applied Physics Letters, Vol. 70, Issue 25
  • DOI: 10.1063/1.119196

Relation between electroabsorption in bulk semiconductors and in quantum wells: The quantum-confined Franz-Keldysh effect
journal, May 1986


Analyzing the physical properties of InGaN multiple quantum well light emitting diodes from nano scale structure
journal, August 2012

  • Wu, Yuh-Renn; Shivaraman, Ravi; Wang, Kuang-Chung
  • Applied Physics Letters, Vol. 101, Issue 8
  • DOI: 10.1063/1.4747532

Carrier localization mechanisms in In x Ga 1 x N/GaN quantum wells
journal, March 2011


Photocurrent spectroscopy of GaAs/ Al x Ga 1 x As quantum wells in an electric field
journal, March 1986


Polarization fields of III-nitrides grown in different crystal orientations
journal, September 2007