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Title: Optical properties of degenerately doped silicon films for applications in thermophotovoltaic systems

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.364076· OSTI ID:435111
; ; ;  [1]; ; ; ;  [2]
  1. Center for Integrated Electronics and Electronics Manufacturing, and Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590 (United States)
  2. Lockheed Martin Inc., Schenectady, New York 12301-1072 (United States)

A detailed study of the dependence of the plasma wavelength and free-carrier absorption on the doping concentration in silicon has been made. Two approaches have been used for introducing impurities into Si to achieve high doping concentration. One was the diffusion technique, using spin-on dopants. The plasma wavelength ({lambda}{sub p}) of these doped films could be adjusted by controlling the diffusion conditions. The minimum plasma wavelength achieved was 4.8 {mu}m. In addition, a significant amount of absorption was observed for the wavelength 2 {mu}m and below. The second approach was doping by ion implantation followed by thermal annealing with a capped layer of doped glass. Implantation with high dosages of B and As followed by high temperature annealing ({gt}1000{degree}C) resulted in a plasma wavelength that could be controlled between 3.5 and 6 {mu}m. The high temperature annealing ({gt}1000{degree}C) that was necessary to activate the dopant atoms and to heal the implantation damage also caused significant redistribution of the dopants. For phosphorous implanted Si, a moderate temperature (800{endash}900{degree}C) was sufficient to activate most of the phosphorous and to heal the implantation damage. The position of the plasma turn-on wavelength for an implantation dose of 2{times}10{sup 16} cm{sup {minus}2} of P was at 2.9 {mu}m. The absorption at 2 {mu}m was less than 25{percent} and the reflection at 10 {mu}m was about 85{percent}. {copyright} {ital 1997 American Institute of Physics.}

OSTI ID:
435111
Journal Information:
Journal of Applied Physics, Vol. 81, Issue 1; Other Information: PBD: Jan 1997
Country of Publication:
United States
Language:
English