Influence of the size dispersion on the emission spectra of the hydrogen passivated Si nanoparticles in SiNx

The influence of the size dispersion on the emission spectra of the hydrogen passivated silicon nanopaticles (Si NPs) in silicon nitride thin films, which are grown by helicon wave plasma-enhanced chemical vapor deposition (HWP-CVD) technique with SiH4, H2 and Ar-diluted 6.25% N2 as the reactant gas sources, have been investigated. Transmission electron microscopy examination shows that Si NPs are isolated from the others by silicon nitride barriers and the sizes of Si NPs in silicon nitride matrix are distributed within a wide range. The luminescent due to quantum confinement effect of Si NPs embedded in the SiNx matrix was guaranteed by adding H2 into film deposition process. The emission correlated to the defects such as excess silicon voids and nonradiative recombination centers have been suppressed and a strong PL with a wide band was observed. The photoluminescence (PL) spectra were investigated under different excitation energy (Eex). It is shown that both the PL peak energy and their full width at half maximum (FWHM) show a decrease trend with decreasing the Eex, and no obvious PL can be observed when the Eex lower than a certain Eex. And at high excitation energy contribution of the smaller particles in size becomes remarkable larger, thus it may be extremely difficult to correlate the PL spectra with the mean size of the Si NPs. These results are explained by quantum confinement effect model taking into account there existing a size distribution of Si NPs in the SiNx matrix.

[1]  Sharka M. Prokes,et al.  Light emission in thermally oxidized porous silicon: Evidence for oxide‐related luminescence , 1993 .

[2]  Chang-Hee Cho,et al.  Photoluminescence of silicon quantum dots in silicon nitride grown by NH3 and SiH4 , 2005 .

[3]  Y. G. Wang,et al.  High-efficiency visible photoluminescence from amorphous silicon nanoparticles embedded in silicon nitride , 2003 .

[4]  Jacob B. Khurgin,et al.  Influence of the size dispersion on the emission spectra of the Si nanostructures , 1996 .

[5]  D. M. Hembree,et al.  Effects of Hydrogen in the Annealing Environment on Photoluminescence from Si Nanoparticles in SiO(2) , 1999 .

[6]  Ian W. Boyd,et al.  Enhancement of luminescence from encapsulated Si nanocrystals in SiO2 with rapid thermal anneals , 2005 .

[7]  Minoru Fujii,et al.  Size-dependent photoluminescence from surface-oxidized Si nanocrystals in a weak confinement regime , 2000 .

[8]  E. P. Gusev,et al.  On the behavior of deuterium in ultrathin SiO2 films upon thermal annealing , 1998 .

[9]  L. Canham.  Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers , 1990 .

[10]  Wei Yu,et al.  AMORPHOUS SILICON NANO-PARTICLES IN A-SiNx:H PREPARED BY HELICON WAVE PLASMA-ENHANCED CHEMICAL VAPOUR DEPOSITION , 2005 .

[11]  Ding Wenge,et al.  Microstructure Modification of Silicon Nanograins Embedded in Silicon Nitride Thin Films , 2006 .

[12]  Delley,et al.  Quantum confinement in Si nanocrystals. , 1993, Physical review. B, Condensed matter.

[13]  Xianbo Liao,et al.  Amorphous silicon nanoparticles in compound films grown on cold substrates for high-efficiency photoluminescence , 2003 .

[14]  Harry A. Atwater,et al.  Defect‐related versus excitonic visible light emission from ion beam synthesized Si nanocrystals in SiO2 , 1996 .

[15]  V. Petrova-Koch,et al.  The luminescence of porous Si: the case for the surface state mechanism , 1993 .

[16]  Z. Y. Zhang,et al.  Optical emission from excess Si defect centers in Si nanostructures. , 2003, Physical review letters.

[17]  Glembocki,et al.  Role of interfacial oxide-related defects in the red-light emission in porous silicon. , 1994, Physical review. B, Condensed matter.

[18]  Robert Elliman,et al.  Effect of particle size on the photoluminescence from hydrogen passivated Si nanocrystals in SiO2 , 2001 .