Charge carrier generation caused by X-rays in organometallic materials

Organometallic compounds play an exceptional role among organic compounds. Due to their structure a number of these compounds demonstrate interesting properties in various phenomena. Organometallic compounds show special prop erties in the case of X-ray absorption owing to considerable differences be tween the absorption coefficients of metals and light elements. The analysi s of processes of charge carrier generation as a result of X-ray absorption in chosen organometallic compounds is the subject of this paper. Spectral dependences of charge carrier photogeneration efficiency around the Cu K-ed ge in copper phthalocyanine and copper acetylacetoniane have been specially considered. It has been observed that the photocurrent spectrum in these m aterials follows the absorption spectrum but mutual relation is not directl y proportional. Experimental results connected with current-voltage and cur rent-intensity characteristics have been analysed, as well. The obtained re lationships have been compared with adequate results connected with charge carrier photogeneration in visible area and UV in organic materials. It has been observed that the X-ray photogeneration of charge carriers in the exa mined range of energy differs from the mechanisms of charge carrier generat ion in visible area and UV. The basic differences arise from the participat ion of secondary electrons, which are generated due to Auger electrons, Com pton effect, and metal fluorescence. The process of charge carrier generati on as a result of X-rays absorption is characterized by strong recombinatio n of charge carriers in channels in which charge carriers are generated by high energetic secondary electrons.