[A high transmittance material in UVc band].

Spectral characteristics of an organic material in acid with different concentrations were investigated in the solution of a proper acid concentration. The results showed that at 252 nm the transmittance T = 56.5%, but at 290 nm the material had a strong absorption peak (epsilon > 10(4) L. (mol.cm)-1). The absorbance A280-298 nm > 8, i.e. T280-298 nm < 10(-8). The band width was about 16 nm. Therefore, this material has conspicuous characteristics such as high transmittance and deep cutoff in the background in ultraviolet-c band. The transmission peak can be shifted in the range of 251-260 nm by changing the pH value of the solution and selecting solution with a different polarity. By analyzing the spectra of the material in acid we found that the two original absorption peaks disappeared, and a new strong absorption peak appeared at 290 nm. Moreover, it seems to be some relation between the two absorption peak intensity and the new peak, which needs to be further studied. Using this result, we can produce high quality UV-filters of this material with traditional coating and colour glass technology.