Sensitized light-induced degradations

Each transparent polymer must be stabilized against light-induced degradation by incorporation by uv stabilizers, uv absorbers should absorb uv light without the formation of free radicals. For commercial purposes, they should absorb under 420 nm, since the maximum sensitivity of many plastics lies between 290 and 360 nm. uv absorbers for cosmetic purposes, however, should absorb under 320 nm, since the human skin shows a sharp maximum sensitivity at 297 nm. 

Sterically hindered amines (HALS) play an important role as stabilizers against the light-induced degradation of polyolefins " the detailed mechanism of their action is still being discussed. Therefore, the method of triplet-sensitized... 

The main aim of this study was to identify physical-chemical factors relevant for long-term stability or degradation of sensitizers of nanocrystalline ZnO and TiO solar cells to determine the influence of the adsorption site. The focus was on light-induced degradation. An analytical formula describing the nature of various... 

Because each device in a multijxmction structure absorbs only a part of the solar spectrum, each produces less current than an optimized single junction device would. It is important to remember that lower-current devices are generally more sensitive to defects, because recombination and trap states are less likely to become saturated with carriers. This means that multijxmction devices tend to be more sensitive to material quality. In amorphous devices it also means that light-induced degradation is more of a problem. This is another reason to use nanocrystalline materials for the narrow-gap device. 

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