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Title: Barrier height inhomogeneity in electrical transport characteristics of InGaN/GaN heterostructure interfaces

Abstract

We have grown InGaN/GaN heterostructures using plasma-assisted molecular beam epitaxy and studied the temperature dependent electrical transport characteristics. The barrier height (φ{sub b}) and the ideally factor (η) estimated using thermionic emission model were found to be temperature dependent. The conventional Richardson plot of ln(J{sub s}/T{sup 2}) versus 1/kT showed two temperature regions (region-I: 400–500 K and region-II: 200–350 K) and it provides Richardson constants (A{sup ∗}) which are much lower than the theoretical value of GaN. The observed variation in the barrier height and the presence of two temperature regions were attributed to spatial barrier inhomogeneities at the heterojunction interface and was explained by assuming a double Gaussian distribution of barrier heights with mean barrier height values 1.61 and 1.21 eV with standard deviation (σ{sub s}{sup 2}) of 0.044 and 0.022 V, respectively. The modified Richardson plot of ln(J{sub s}/T{sup 2}) − (q{sup 2}σ{sub s}{sup 2}/2k{sup 2}T{sup 2}) versus 1/kT for two temperature regions gave mean barrier height values as 1.61 eV and 1.22 eV with Richardson constants (A{sup ∗}) values 25.5 Acm{sup −2}K{sup −2} and 43.9 Acm{sup −2}K{sup −2}, respectively, which are very close to the theoretical value. The observed barrier height inhomogeneities were interpreted on the basismore » of the existence of a double Gaussian distribution of barrier heights at the interface.« less

Authors:
 [1];  [2]; ; ; ;  [1]
  1. Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India)
  2. (India)
Publication Date:
OSTI Identifier:
22454480
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 3; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; GALLIUM NITRIDES; GAUSS FUNCTION; INTERFACES; MOLECULAR BEAM EPITAXY; TEMPERATURE DEPENDENCE; THERMIONIC EMISSION

Citation Formats

Roul, Basanta, Central Research Laboratory, Bharat Electronics, Bangalore 560013, Mukundan, Shruti, Chandan, Greeshma, Mohan, Lokesh, and Krupanidhi, S. B., E-mail: sbk@mrc.iisc.ernet.in. Barrier height inhomogeneity in electrical transport characteristics of InGaN/GaN heterostructure interfaces. United States: N. p., 2015. Web. doi:10.1063/1.4916264.
Roul, Basanta, Central Research Laboratory, Bharat Electronics, Bangalore 560013, Mukundan, Shruti, Chandan, Greeshma, Mohan, Lokesh, & Krupanidhi, S. B., E-mail: sbk@mrc.iisc.ernet.in. Barrier height inhomogeneity in electrical transport characteristics of InGaN/GaN heterostructure interfaces. United States. doi:10.1063/1.4916264.
Roul, Basanta, Central Research Laboratory, Bharat Electronics, Bangalore 560013, Mukundan, Shruti, Chandan, Greeshma, Mohan, Lokesh, and Krupanidhi, S. B., E-mail: sbk@mrc.iisc.ernet.in. Sun . "Barrier height inhomogeneity in electrical transport characteristics of InGaN/GaN heterostructure interfaces". United States. doi:10.1063/1.4916264.
@article{osti_22454480,
title = {Barrier height inhomogeneity in electrical transport characteristics of InGaN/GaN heterostructure interfaces},
author = {Roul, Basanta and Central Research Laboratory, Bharat Electronics, Bangalore 560013 and Mukundan, Shruti and Chandan, Greeshma and Mohan, Lokesh and Krupanidhi, S. B., E-mail: sbk@mrc.iisc.ernet.in},
abstractNote = {We have grown InGaN/GaN heterostructures using plasma-assisted molecular beam epitaxy and studied the temperature dependent electrical transport characteristics. The barrier height (φ{sub b}) and the ideally factor (η) estimated using thermionic emission model were found to be temperature dependent. The conventional Richardson plot of ln(J{sub s}/T{sup 2}) versus 1/kT showed two temperature regions (region-I: 400–500 K and region-II: 200–350 K) and it provides Richardson constants (A{sup ∗}) which are much lower than the theoretical value of GaN. The observed variation in the barrier height and the presence of two temperature regions were attributed to spatial barrier inhomogeneities at the heterojunction interface and was explained by assuming a double Gaussian distribution of barrier heights with mean barrier height values 1.61 and 1.21 eV with standard deviation (σ{sub s}{sup 2}) of 0.044 and 0.022 V, respectively. The modified Richardson plot of ln(J{sub s}/T{sup 2}) − (q{sup 2}σ{sub s}{sup 2}/2k{sup 2}T{sup 2}) versus 1/kT for two temperature regions gave mean barrier height values as 1.61 eV and 1.22 eV with Richardson constants (A{sup ∗}) values 25.5 Acm{sup −2}K{sup −2} and 43.9 Acm{sup −2}K{sup −2}, respectively, which are very close to the theoretical value. The observed barrier height inhomogeneities were interpreted on the basis of the existence of a double Gaussian distribution of barrier heights at the interface.},
doi = {10.1063/1.4916264},
journal = {AIP Advances},
number = 3,
volume = 5,
place = {United States},
year = {Sun Mar 15 00:00:00 EDT 2015},
month = {Sun Mar 15 00:00:00 EDT 2015}
}