Stability
against oxygen is an important factor affecting the performance of
organic semiconductor devices. Improving photooxidation stability can
prolong the service life of the device and maintain the mechanical and
photoelectric properties of the device. Generally, various encapsulation
methods from molecular structure to macroscopic device level are used to
improve photooxidation stability. Here, we adopted a crystallization
strategy to allow
14H-spiro[dibenzo[c,h]a-cridine-7,9′-uorene] (SFDBA) to
pack tightly to resist fluorescence decay caused by oxidation. In this
case, the inert group of SFDBA acts as a “steric armor”, protecting
the photosensitive group from being attacked by oxygen. Therefore,
compared with the fluorescence quenching of SFDBA powder under two hours
of sunlight, SFDBA crystal can maintain its fluorescence emission for
more than eight hours under the same conditions. Furthermore, the
photoluminescence quantum yields (PLQYs) of the crystalline film is
327.37 % higher than that of the amorphous film. It shows that the
crystallization strategy is an effective method to resist oxidation.
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