Spectroscopic study of the low-dimensional (C3H7NH3)2CdCl4 crystal irradiated with X-rays

The optical absorption spectra of the two-dimensional crystals of n-(C3H7NH3)2CdCl4 induced by X-ray irradiation at 20 K were studied and compared with those for the as-received sample. It has been found that X-irradiation causes effects similar to those observed in the related crystals of (Cn H2n+1NH3)2CdCl4 (n=1,2). New optical absorption bands (IR bands) were found in the region 10-17 kcm -1, besides the absorption band of the Cl2- molecular center characteristic of this compound. The absorption intensities of these bands decrease at temperatures higher than 40 K accompanying the decrease of the Cl2- concentration in n-(C3H7NH3)2CdCl4 crystals. These IR bands are assigned to the electron-trapped center where an electron is trapped by an alkylammonium head in the neighborhood of a Cl- vacancy. Such a model was found to be in good agreement with the results of the X-ray luminescence and thermoluminescence study. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)