“
“The dominant recombination processes controlling the carrier lifetime in n-type 4H-SiC epitaxial layers grown with low concentrations of the Z(1/2) defect (the dominant bulk lifetime killer), where Z(1/2) no longer determines the lifetime, have been investigated by studying the variation in the carrier lifetime with temperature. The temperature dependent lifetimes were obtained primarily by low-injection photoluminescence decay for several low-Z(1/2) epilayers over a wide temperature range. The results Selleckchem CT99021 were
fitted to simulations of the temperature dependent recombination rate, where bulk, surface and interface recombination was considered.
No significant contribution BTSA1 concentration from other bulk defects was observed, and upper limits to the bulk recombination rate were found to be consistent with the low Z(1/2) concentrations measured in these materials. There was also no significant contribution from carrier capture at the epilayer/substrate interface, which is consistent with behavior expected at low injection for low-doped epilayers grown on n(+) substrates. Corresponding high-injection measurements exhibited very different behavior, consistent with the surface/interface under flat-band conditions. Consequently, it is concluded that for low-Z(1/2) materials, control of the carrier lifetime has not been transferred from Z(1/2)
to another bulk defect, but is instead dominated by surface and interface recombination. Simulations suggest that further enhancement of the total lifetime https://www.selleckchem.com/products/nepicastat-hydrochloride.html under the high injection conditions of a device structure would require very thick epilayers, effectively passivated surface and interface recombination and a further reduction in the remaining Z(1/2) concentrations. The temperature dependence of the low-injection carrier lifetime was also found to provide a method to estimate the surface band bending and the surface defect density. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3466745]“
“This work aims to evaluate the performance of glass/sisal hybrid composites focusing on mechanical (flexural and impact) and dynamic mechanical analyses (DMTA). Hybrid composites with different fiber loadings and different volume ratios between glass and sisal were studied. The effect of the fiber length has also been investigated. The densities of the composites were compared with the theoretical values, showing agreement with the rule of mixtures. The results obtained in the flexural and impact analysis revealed that, in general, the properties were always higher for higher overall reinforcement content.