Photodegradation drawbacks

The photoconductivity of polysilanes was described in Section 5.8, and their electroluminescence is covered in Section 5.9.2. These properties make polysilanes possible components of polymer light-emitting diodes, either as charge transport layers or as the actual emissive materials.146 A drawback of the polysilanes is their photodegradation under ultraviolet irradiation, a problem which must be overcome if polysilanes are to become commercially useful. 

A major drawback of the spectrophotometric analysis is the fact that many photodegradation reactions provoke no or only negligible spectral changes. This leads to the fact that many photoreactions cannot be registered accordingly. 

The use of IR spectroscopy for the detection of photodegradants in solid drug substances has also been reported in literature (16). The major drawback of this method is its limited sensitivity. Normally changes can only be detected when the degradation products exceed 1%. 

There are several drawbacks for LC photoaligning materials prepared by photochemical reaction and by photodegradation in particular ... 

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