ABSTRACT
Organic materials have recently attracted major attention because they demonstrated, in the case of other electronic/optoelectronic devices, room-temperature operation, low environmental impact, low fabrication costs, and the possibility of fabricating transparent and flexible devices, allowing unprecedented and integrated device functions and architectures. Organic Semiconducting Single Crystals (OSSCs) can be used as effective direct x-ray detectors. 4-hydroxycyanobenzene (4HCB) based detectors have been described in detail as an example, but other OSSCs present similar properties and provide a reliable response even after exposure to significant doses of x-ray irradiation and after being aged for up to 1 month. 4HCB crystals have rather complex crystal unit cell structures, which can characterized by x-ray diffraction methods, and which result from enhanced hydrogen-bond formation between the –OH and –CN groups of the molecule. Photocurrent spectroscopy analyses allowed the effective electrical bandgap of 4HCB crystals to be determined, estimated at about 4 eV.
