TY - JOUR
T1 - White light, luminescence from nano-ZnS doped porous silicon
AU - Cheah, Kok Wai
AU - Xu, Ling
AU - Huang, Xinfan
N1 - Copyright:
Copyright 2004 Elsevier Science B.V., Amsterdam. All rights reserved.
PY - 2002
Y1 - 2002
N2 - Nano-ZnS was deposited into porous silicon. By varying the concentration of Zn2+ ion solution during nano-ZnS formation, the amount of nano-ZnS in porous silicon host can be controlled. The doped porous silicon exhibited a gradual shift in its photoluminescence peak from red to blue as a function of the nano-ZnS coverage. At an optimum doping, white light photoluminescence was obtained. A study in the luminescence lifetime showed that the radiative recombination at the blue end of the visible spectrum was due to nano-ZnS, whereas, luminescence emission at the red end of the visible spectrum came from porous silicon. The latter luminescence was due to in part tunneling of excited electrons from nano-ZnS into porous silicon and in part direct excitation of porous silicon layer. Time-resolved photoluminescence also showed that radiative recombination was effectively dominated by the nano-ZnS. Photoluminescence excitation result revealed the presence of two excitation levels; one belonged to nano-ZnS at near uv region, and another at about 520 nm from the surface states of porous silicon and nano-ZnS. The doping of nano-ZnS into porous silicon demonstrates that luminescence color tuning is possible when an appropriate functional material is introduced into porous silicon.
AB - Nano-ZnS was deposited into porous silicon. By varying the concentration of Zn2+ ion solution during nano-ZnS formation, the amount of nano-ZnS in porous silicon host can be controlled. The doped porous silicon exhibited a gradual shift in its photoluminescence peak from red to blue as a function of the nano-ZnS coverage. At an optimum doping, white light photoluminescence was obtained. A study in the luminescence lifetime showed that the radiative recombination at the blue end of the visible spectrum was due to nano-ZnS, whereas, luminescence emission at the red end of the visible spectrum came from porous silicon. The latter luminescence was due to in part tunneling of excited electrons from nano-ZnS into porous silicon and in part direct excitation of porous silicon layer. Time-resolved photoluminescence also showed that radiative recombination was effectively dominated by the nano-ZnS. Photoluminescence excitation result revealed the presence of two excitation levels; one belonged to nano-ZnS at near uv region, and another at about 520 nm from the surface states of porous silicon and nano-ZnS. The doping of nano-ZnS into porous silicon demonstrates that luminescence color tuning is possible when an appropriate functional material is introduced into porous silicon.
UR - http://www.scopus.com/inward/record.url?scp=0036343553&partnerID=8YFLogxK
M3 - Conference article
AN - SCOPUS:0036343553
SN - 0272-9172
VL - 686
SP - 201
EP - 207
JO - Materials Research Society Symposium Proceedings
JF - Materials Research Society Symposium Proceedings
T2 - Materials Issues in Novel Si-Based Technology
Y2 - 26 November 2001 through 28 November 2001
ER -