Impurity Effects in ZnO and Nitrogen-Doped ZnO Thin Films Fabricated by MOCVD

Xiaonan Li; Sally E. Asher; Sukit Limpijumnong; Brian M. Keyes; Craig L. Perkins; Teresa M. Barnes; Helio R. Moutinho; Joseph M. Luther; S. B. Zhang; Su Huai Wei; Timothy J. Coutts

doi:10.1016/j.jcrysgro.2005.10.050

Impurity Effects in ZnO and Nitrogen-Doped ZnO Thin Films Fabricated by MOCVD

Xiaonan Li, Sally E. Asher, Sukit Limpijumnong, Brian M. Keyes, Craig L. Perkins, Teresa M. Barnes, Helio R. Moutinho, Joseph M. Luther, S. B. Zhang, Su Huai Wei, Timothy J. Coutts

Research output: Contribution to journal › Article › peer-review

63 Scopus Citations

Abstract

We studied the role of impurities in nitrogen-doped ZnO thin film to understand the difficulty of producing p-type ZnO via nitrogen doping. The ZnO:N films were fabricated by low-pressure metal-organic chemical vapor deposition (MOCVD) using diethylzinc (DEZ) and nitric oxide (NO) precursors. Although very high levels of nitrogen incorporation were observed (∼10²¹ cm^-3), acceptor concentrations were typically low (10 ¹⁴-10¹⁷ cm^-3). The investigation suggests that the low carrier concentrations are possibly due to compensation and passivation effects by hydrogen and carbon impurities unintentionally incorporated into the films from the metal-organic precursor. X-ray photoelectron spectroscopy (XPS) demonstrated that carbon was a bulk impurity in MOCVD-grown films. Secondary-ion mass spectrometry (SIMS) analysis confirmed the presence of carbon and indicated that hydrogen was also a bulk impurity. The concentration of carbon contaminant was found to increase with nitrogen doping. Both XPS and Fourier transform infrared spectroscopy (FTIR) data indicated that defect complexes (CH_x, NH_x, and NC_x) are likely present in MOCVD-grown ZnO films. First-principles calculations predict that the N _O-H and (NC)_O defect complexes are neutral and 1 ⁺ charge state; therefore, the existing carbon and hydrogen passivate the nitrogen acceptor species. Thus, we believe a low hole concentration in MOCVD-fabricated ZnO:N films are partially due to inadvertent passivation by hydrogen and carbon.

Original language	American English
Pages (from-to)	94-100
Number of pages	7
Journal	Journal of Crystal Growth
Volume	287
Issue number	1
DOIs	https://doi.org/10.1016/j.jcrysgro.2005.10.050 https://doi.org/10.1016/j.jcrysgro.2005.10.050
State	Published - 2006
Event	Proceedings of the International Conference on Materials for Advanced Technologies (ICMAT 2005) Symposium N ZnO and Related Materials - Duration: 3 Jul 2005 → 8 Jul 2005

NREL Publication Number

NREL/JA-520-38037

Keywords

A1. Impurities
A3. Doping chemical vapor deposition processes
B1. Oxide
B2. Semiconducting II-VI materials

Access to Document

Cite this

Li, X., Asher, S. E., Limpijumnong, S., Keyes, B. M., Perkins, C. L., Barnes, T. M., Moutinho, H. R., Luther, J. M., Zhang, S. B., Wei, S. H., & Coutts, T. J. (2006). Impurity Effects in ZnO and Nitrogen-Doped ZnO Thin Films Fabricated by MOCVD. Journal of Crystal Growth, 287(1), 94-100. https://doi.org/10.1016/j.jcrysgro.2005.10.050, https://doi.org/10.1016/j.jcrysgro.2005.10.050

@article{620288e3681c4c24b35027b662202c7b,

title = "Impurity Effects in ZnO and Nitrogen-Doped ZnO Thin Films Fabricated by MOCVD",

abstract = "We studied the role of impurities in nitrogen-doped ZnO thin film to understand the difficulty of producing p-type ZnO via nitrogen doping. The ZnO:N films were fabricated by low-pressure metal-organic chemical vapor deposition (MOCVD) using diethylzinc (DEZ) and nitric oxide (NO) precursors. Although very high levels of nitrogen incorporation were observed (∼1021 cm-3), acceptor concentrations were typically low (10 14-1017 cm-3). The investigation suggests that the low carrier concentrations are possibly due to compensation and passivation effects by hydrogen and carbon impurities unintentionally incorporated into the films from the metal-organic precursor. X-ray photoelectron spectroscopy (XPS) demonstrated that carbon was a bulk impurity in MOCVD-grown films. Secondary-ion mass spectrometry (SIMS) analysis confirmed the presence of carbon and indicated that hydrogen was also a bulk impurity. The concentration of carbon contaminant was found to increase with nitrogen doping. Both XPS and Fourier transform infrared spectroscopy (FTIR) data indicated that defect complexes (CHx, NHx, and NCx) are likely present in MOCVD-grown ZnO films. First-principles calculations predict that the N O-H and (NC)O defect complexes are neutral and 1 + charge state; therefore, the existing carbon and hydrogen passivate the nitrogen acceptor species. Thus, we believe a low hole concentration in MOCVD-fabricated ZnO:N films are partially due to inadvertent passivation by hydrogen and carbon.",

keywords = "A1. Impurities, A3. Doping chemical vapor deposition processes, B1. Oxide, B2. Semiconducting II-VI materials",

author = "Xiaonan Li and Asher, {Sally E.} and Sukit Limpijumnong and Keyes, {Brian M.} and Perkins, {Craig L.} and Barnes, {Teresa M.} and Moutinho, {Helio R.} and Luther, {Joseph M.} and Zhang, {S. B.} and Wei, {Su Huai} and Coutts, {Timothy J.}",

year = "2006",

doi = "10.1016/j.jcrysgro.2005.10.050",

language = "American English",

volume = "287",

pages = "94--100",

journal = "Journal of Crystal Growth",

issn = "0022-0248",

publisher = "Elsevier",

number = "1",

note = "Proceedings of the International Conference on Materials for Advanced Technologies (ICMAT 2005) Symposium N ZnO and Related Materials ; Conference date: 03-07-2005 Through 08-07-2005",

}

TY - JOUR

T1 - Impurity Effects in ZnO and Nitrogen-Doped ZnO Thin Films Fabricated by MOCVD

AU - Li, Xiaonan

AU - Asher, Sally E.

AU - Limpijumnong, Sukit

AU - Keyes, Brian M.

AU - Perkins, Craig L.

AU - Barnes, Teresa M.

AU - Moutinho, Helio R.

AU - Luther, Joseph M.

AU - Zhang, S. B.

AU - Wei, Su Huai

AU - Coutts, Timothy J.

PY - 2006

Y1 - 2006

N2 - We studied the role of impurities in nitrogen-doped ZnO thin film to understand the difficulty of producing p-type ZnO via nitrogen doping. The ZnO:N films were fabricated by low-pressure metal-organic chemical vapor deposition (MOCVD) using diethylzinc (DEZ) and nitric oxide (NO) precursors. Although very high levels of nitrogen incorporation were observed (∼1021 cm-3), acceptor concentrations were typically low (10 14-1017 cm-3). The investigation suggests that the low carrier concentrations are possibly due to compensation and passivation effects by hydrogen and carbon impurities unintentionally incorporated into the films from the metal-organic precursor. X-ray photoelectron spectroscopy (XPS) demonstrated that carbon was a bulk impurity in MOCVD-grown films. Secondary-ion mass spectrometry (SIMS) analysis confirmed the presence of carbon and indicated that hydrogen was also a bulk impurity. The concentration of carbon contaminant was found to increase with nitrogen doping. Both XPS and Fourier transform infrared spectroscopy (FTIR) data indicated that defect complexes (CHx, NHx, and NCx) are likely present in MOCVD-grown ZnO films. First-principles calculations predict that the N O-H and (NC)O defect complexes are neutral and 1 + charge state; therefore, the existing carbon and hydrogen passivate the nitrogen acceptor species. Thus, we believe a low hole concentration in MOCVD-fabricated ZnO:N films are partially due to inadvertent passivation by hydrogen and carbon.

AB - We studied the role of impurities in nitrogen-doped ZnO thin film to understand the difficulty of producing p-type ZnO via nitrogen doping. The ZnO:N films were fabricated by low-pressure metal-organic chemical vapor deposition (MOCVD) using diethylzinc (DEZ) and nitric oxide (NO) precursors. Although very high levels of nitrogen incorporation were observed (∼1021 cm-3), acceptor concentrations were typically low (10 14-1017 cm-3). The investigation suggests that the low carrier concentrations are possibly due to compensation and passivation effects by hydrogen and carbon impurities unintentionally incorporated into the films from the metal-organic precursor. X-ray photoelectron spectroscopy (XPS) demonstrated that carbon was a bulk impurity in MOCVD-grown films. Secondary-ion mass spectrometry (SIMS) analysis confirmed the presence of carbon and indicated that hydrogen was also a bulk impurity. The concentration of carbon contaminant was found to increase with nitrogen doping. Both XPS and Fourier transform infrared spectroscopy (FTIR) data indicated that defect complexes (CHx, NHx, and NCx) are likely present in MOCVD-grown ZnO films. First-principles calculations predict that the N O-H and (NC)O defect complexes are neutral and 1 + charge state; therefore, the existing carbon and hydrogen passivate the nitrogen acceptor species. Thus, we believe a low hole concentration in MOCVD-fabricated ZnO:N films are partially due to inadvertent passivation by hydrogen and carbon.

KW - A1. Impurities

KW - A3. Doping chemical vapor deposition processes

KW - B1. Oxide

KW - B2. Semiconducting II-VI materials

UR - http://www.scopus.com/inward/record.url?scp=29944446781&partnerID=8YFLogxK

U2 - 10.1016/j.jcrysgro.2005.10.050

DO - 10.1016/j.jcrysgro.2005.10.050

M3 - Article

AN - SCOPUS:29944446781

SN - 0022-0248

VL - 287

SP - 94

EP - 100

JO - Journal of Crystal Growth

JF - Journal of Crystal Growth

IS - 1

T2 - Proceedings of the International Conference on Materials for Advanced Technologies (ICMAT 2005) Symposium N ZnO and Related Materials

Y2 - 3 July 2005 through 8 July 2005

ER -

Impurity Effects in ZnO and Nitrogen-Doped ZnO Thin Films Fabricated by MOCVD

Abstract

NREL Publication Number

Keywords

Access to Document

Other files and links

Fingerprint

Cite this