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Title: Dissolution of Oxygen Precipitate Nuclei in n-Type CZ-Si Wafers to Improve Their Material Quality: Experimental Results

Abstract

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 oxygen analysis using Fourier transform infrared spectra and injection-level dependence of MCLT.

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
OSTI Identifier:
1343089
Report Number(s):
NREL/JA-5J00-66519
Journal ID: ISSN 2156-3381
DOE Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Journal of Photovoltaics; Journal Volume: 7; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; spatial diversity; charge carrier lifetime; chemical etching; optical furnace; silicon solar cells

Citation Formats

Sopori, Bhushan, Basnyat, Prakash, Devayajanam, Srinivas, Tan, Teh, Upadhyaya, Ajay, Tate, Keith, Rohatgi, Ajeet, and Xu, Han. Dissolution of Oxygen Precipitate Nuclei in n-Type CZ-Si Wafers to Improve Their Material Quality: Experimental Results. United States: N. p., 2017. Web. doi:10.1109/JPHOTOV.2016.2621345.
Sopori, Bhushan, Basnyat, Prakash, Devayajanam, Srinivas, Tan, Teh, Upadhyaya, Ajay, Tate, Keith, Rohatgi, Ajeet, & Xu, Han. Dissolution of Oxygen Precipitate Nuclei in n-Type CZ-Si Wafers to Improve Their Material Quality: Experimental Results. United States. doi:10.1109/JPHOTOV.2016.2621345.
Sopori, Bhushan, Basnyat, Prakash, Devayajanam, Srinivas, Tan, Teh, Upadhyaya, Ajay, Tate, Keith, Rohatgi, Ajeet, and Xu, Han. Sun . "Dissolution of Oxygen Precipitate Nuclei in n-Type CZ-Si Wafers to Improve Their Material Quality: Experimental Results". United States. doi:10.1109/JPHOTOV.2016.2621345.
@article{osti_1343089,
title = {Dissolution of Oxygen Precipitate Nuclei in n-Type CZ-Si Wafers to Improve Their Material Quality: Experimental Results},
author = {Sopori, Bhushan and Basnyat, Prakash and Devayajanam, Srinivas and Tan, Teh and Upadhyaya, Ajay and Tate, Keith and Rohatgi, Ajeet and Xu, Han},
abstractNote = {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 oxygen analysis using Fourier transform infrared spectra and injection-level dependence of MCLT.},
doi = {10.1109/JPHOTOV.2016.2621345},
journal = {IEEE Journal of Photovoltaics},
number = 1,
volume = 7,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2017},
month = {Sun Jan 01 00:00:00 EST 2017}
}