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Title: Oxygen migration enthalpy likely limits oxide precipitate dissolution during tabula rasa

Authors:
ORCiD logo [1];  [2];  [1];  [1];  [3];  [3];  [1]
  1. Mechanical Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
  2. Mechanical Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA, Department of Electronics and Nanoengineering, Aalto University, 02150 Espoo, Finland
  3. National Renewable Energy Laboratory, Golden, Colorado 80401, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1394672
Grant/Contract Number:
SETP DE-EE00030301
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 111; Journal Issue: 13; Related Information: CHORUS Timestamp: 2018-02-15 01:08:53; Journal ID: ISSN 0003-6951
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Looney, E. E., Laine, H. S., Youssef, A., Jensen, M. A., LaSalvia, V., Stradins, P., and Buonassisi, T. Oxygen migration enthalpy likely limits oxide precipitate dissolution during tabula rasa. United States: N. p., 2017. Web. doi:10.1063/1.4987144.
Looney, E. E., Laine, H. S., Youssef, A., Jensen, M. A., LaSalvia, V., Stradins, P., & Buonassisi, T. Oxygen migration enthalpy likely limits oxide precipitate dissolution during tabula rasa. United States. doi:10.1063/1.4987144.
Looney, E. E., Laine, H. S., Youssef, A., Jensen, M. A., LaSalvia, V., Stradins, P., and Buonassisi, T. Mon . "Oxygen migration enthalpy likely limits oxide precipitate dissolution during tabula rasa". United States. doi:10.1063/1.4987144.
@article{osti_1394672,
title = {Oxygen migration enthalpy likely limits oxide precipitate dissolution during tabula rasa},
author = {Looney, E. E. and Laine, H. S. and Youssef, A. and Jensen, M. A. and LaSalvia, V. and Stradins, P. and Buonassisi, T.},
abstractNote = {},
doi = {10.1063/1.4987144},
journal = {Applied Physics Letters},
number = 13,
volume = 111,
place = {United States},
year = {Mon Sep 25 00:00:00 EDT 2017},
month = {Mon Sep 25 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on September 25, 2018
Publisher's Accepted Manuscript

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  • In industrial silicon solar cells, oxygen-related defects lower device efficiencies by up to 20% (rel.). In order to mitigate these defects, a high-temperature homogenization anneal called tabula rasa (TR) that has been used in the electronics industry is now proposed for use in solar-grade wafers. This work addresses the kinetics of tabula rasa by elucidating the activation energy governing oxide precipitate dissolution, which is found to be 2.6 +/- 0.5 eV. This value is consistent within uncertainty to the migration enthalpy of oxygen interstitials in silicon, implying TR to be kinetically limited by oxygen point-defect diffusion. This large activation energymore » is observed to limit oxygen precipitate dissolution during standard TR conditions, suggesting that more aggressive annealing conditions than conventionally used are required for complete bulk microdefect mitigation.« less
  • Oxygen was added to T-111 (Ta--8W--2Hf, wt. %) at 820 and 990/sup 0/C at an oxygen pressure of about 3 x 10/sup -4/ Torr (4 x 10/sup -2/ N/m/sup 2/). The technique employed permitted predetermined and reproducible doping of T-111 up to 3.0 at. % oxygen. Based on the temperature dependence of the doping reaction, it is concluded that the initial rates of oxygen pickup are probably controlled by solution of oxygen into the T-111 lattice. Although hafnium oxides are more stable than those of tantalum or tungsten, analyses of extracted residues indicate that the latter oxides predominate in themore » as-doped specimens, presumably because of the higher concentrations of tantalum and tungsten in the alloy. However, high-temperature annealing promotes gettering of dissolved oxygen and of other oxides to form hafnium oxides. Small amounts of tantalum and tungsten oxides were still present after high-temperature annealing. Tungsten oxide (WO/sub 3/) volatilizes slightly from the surface of T-111 at 990/sup 0/C. The vaporization of WO/sub 3/ has no apparent affect on the doping reaction.« less
  • We present experimental results which show that oxygen-related precipitate nuclei (OPN) present in p-doped, n-type, Czochralski wafers can be dissolved using a flash-annealing process, yielding very high quality wafers for high-efficiency solar cells. Flash annealing consists of heating a wafer in an optical furnace to temperature between 1150 and 1250 degrees C for a short time. This process produces a large increase in the minority carrier lifetime (MCLT) and homogenizes each wafer. We have tested wafers from different axial locations of two ingots. All wafers reach nearly the same high value of MCLT. The OPN dissolution is confirmed by oxygenmore » analysis using Fourier transform infrared spectra and injection-level dependence of MCLT.« less
  • Cited by 5
  • While the recent establishment of the role of thermophoresis/diffusion-driven oxygen migration during resistance switching in metal oxide memristors provided critical insights required for memristor modeling, extended investigations of the role of oxygen migration during ageing and failure remain to be detailed. Such detailing will enable failure-tolerant design, which can lead to enhanced performance of memristor-based next-generation storage-class memory. Furthermore, we directly observed lateral oxygen migration using in-situ synchrotron x-ray absorption spectromicroscopy of HfO x memristors during initial resistance switching, wear over millions of switching cycles, and eventual failure, through which we determined potential physical causes of failure. Using this information,more » we reengineered devices to mitigate three failure mechanisms and demonstrated an improvement in endurance of about three orders of magnitude.« less