In order to successfully employ and exploit the novel and peculiar properties of OSSCs recently discovered and described in the previous section, it is necessary to achieve a full characterization of the electrical response to X-rays of different energies and doses. We have only studied the effect of 35keV X-rays with doses ranging from 20 to 170mGy/s, since we could only have access to such an X-ray source. The possibility of accessing ELETTRA facilities will enable us to achieve a twofold goal: 1- assess the potentialities and the limitations of OSSCs used as room temperature X-ray detectors. Our study, limited to 35keV X-rays need to be extended to lower energies and different doses, such as the ones available at the XXXX beamline to characterize and identify the best operating and performing conditions for OSSCs in view of either medical or civil security applications. 2- Investigate the X-ray photon-to-electron conversion processes from a fundamental point of view. As a matter of fact, the understanding of the electronic behaviour of organic semiconductors is still far from being complete. In particular, the charge transport mechanisms in these materials are still under debate, and the models under discussion range from hopping to band-like transport, possibly even involving more exotic phenomena like nuclear tunnelling. In this view, organic semiconducting single crystals (OSSCs), due to their regular constitution and to the absence of defects, grain boundaries and amorphous zones, represent good model systems for investigating charge transport phenomena and we have carried out a large amount of research in this direction [6,7], including work performed at ELETTRA [8,9]. Our preliminary results on photon-to-electron conversion and electron transport of OSSCs under X-rays, show an unexpected behaviour, reported in Figure 3. The Current-Voltage curves of OSSCs under X-ray irradiation do not follow the same and typical SCLC behaviour as in the dark, indicating that some peculiar and novel mechanisms may be activated and offer a very interesting opportunity to deepen the understanding of transport processes in organic materials.
X-ray detection properties of organic semiconducting single crystals / Beatrice Fraboni. - (2012).
X-ray detection properties of organic semiconducting single crystals
FRABONI, BEATRICE
2012
Abstract
In order to successfully employ and exploit the novel and peculiar properties of OSSCs recently discovered and described in the previous section, it is necessary to achieve a full characterization of the electrical response to X-rays of different energies and doses. We have only studied the effect of 35keV X-rays with doses ranging from 20 to 170mGy/s, since we could only have access to such an X-ray source. The possibility of accessing ELETTRA facilities will enable us to achieve a twofold goal: 1- assess the potentialities and the limitations of OSSCs used as room temperature X-ray detectors. Our study, limited to 35keV X-rays need to be extended to lower energies and different doses, such as the ones available at the XXXX beamline to characterize and identify the best operating and performing conditions for OSSCs in view of either medical or civil security applications. 2- Investigate the X-ray photon-to-electron conversion processes from a fundamental point of view. As a matter of fact, the understanding of the electronic behaviour of organic semiconductors is still far from being complete. In particular, the charge transport mechanisms in these materials are still under debate, and the models under discussion range from hopping to band-like transport, possibly even involving more exotic phenomena like nuclear tunnelling. In this view, organic semiconducting single crystals (OSSCs), due to their regular constitution and to the absence of defects, grain boundaries and amorphous zones, represent good model systems for investigating charge transport phenomena and we have carried out a large amount of research in this direction [6,7], including work performed at ELETTRA [8,9]. Our preliminary results on photon-to-electron conversion and electron transport of OSSCs under X-rays, show an unexpected behaviour, reported in Figure 3. The Current-Voltage curves of OSSCs under X-ray irradiation do not follow the same and typical SCLC behaviour as in the dark, indicating that some peculiar and novel mechanisms may be activated and offer a very interesting opportunity to deepen the understanding of transport processes in organic materials.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
