Time-Resolved Photoluminescence in a-Si1-xCx:H

1996 ◽  
Vol 420 ◽  
Author(s):  
Leandro R. Tessler ◽  
Lucicleide R. Cirino

AbstractThe dependence of the photoluminescence (PL) decay on temperature and composition of a series of amorphous silicon-carbon alloys (a-Si1-xCx:H) with 0 <x <0.4 was studied. The samples were prepared by “low power” PECVD from SiH4/CH4 gas mixtures. The decay curves are non-exponential and can be described as lifetime distributions (LTD). For pure a-Si:H at 17 K the peak of the LTD is of the order of 5×10-4 sec. It shifts to shorter lifetimes as x or the temperature increases. Samples with x > 0.3 present in addition a faster peak with maximum at 10-8 sec. The fast peak is almost temperature independent. The slow component shifts to shorter lifetimes as the temperature increases, and vanishes at room temperature. The presence of the fast peak is interpreted as due to a change in the radiative recombination mechanism. We associate this peak to the recombination of trapped “excitons”.

Author(s):  
Д.В. Юрасов ◽  
Н.А. Байдакова ◽  
А.Н. Яблонский ◽  
А.В. Новиков

Light-emitting properties of Ge-on-Si(001) layers doped by Sb were studied by stationary and time-resolved photoluminescence (PL) at room temperature. It was obtained that the PL intensity of n-Ge/Si(001) structures is maximized when the doping level is close to the equilibrium solubility of Sb in Ge (~1019 cm-3) which is in accordance with the previously published data. Time-resolved studies of the direct-related PL signal have shown that both the donor density and the growth conditions of doped layer, in particular, the growth temperature influence the PL kinetics. It was obtained that the increase of doping level leads to the decrease of the characteristic carrier lifetime. Moreover, usage of low growth temperatures which is needed to form the doped n-Ge layers also results in shortening of the carrier lifetime as compared with Ge layers grown at high temperatures. It was found that rapid thermal anneal at proper conditions could partially compensate the above mentioned detrimental effects and lead to the increase of both the PL intensity and carrier lifetime.


2020 ◽  
Vol 8 (32) ◽  
pp. 11201-11208
Author(s):  
Yang Mi ◽  
Yaoyao Wu ◽  
Jinchun Shi ◽  
Sheng-Nian Luo

We have achieved single-mode whispering-gallery-mode lasing in CdS microflakes with sharp linewidth (∼0.12 nm) and high quality factor (∼4200). Such lasers are superior to previous CdS lasers in these lasing parameters. Through time-resolved photoluminescence measurements, electron–hole plasma recombination is established to be the lasing mechanism. The radiative recombination rate of CdS microflakes is enhanced by a factor of ∼4.7 due to the Purcell effect.


2013 ◽  
Vol 740-742 ◽  
pp. 235-238
Author(s):  
Hitoshi Habuka ◽  
Masaki Tsuji ◽  
Yusuke Ando

The silicon carbide thin film formation process, completely performed at room temperature, was developed by argon plasma and a chemical vapor deposition using monomethylsilane gas. Silicon-carbon bonds were found to exist in the obtained film, the surface of which could remain specular after exposure to hydrogen chloride gas at 800 oC. The silicon dangling bonds formed at the silicon surface by the argon plasma are considered to react with the monomethylsilane molecules at room temperature to produce the amorphous silicon carbide film.


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