In recent years, the development of the organic electronics has led to the employment of organic materials as the basis for many electronic devices, such as organic light emitting diodes, organic field effect transistors, organic solar cells and radiation sensors. As regards radiation sensors, the studies reported in literature mainly refer to devices based on thin film organic semiconductors, which, however, present problems due to instability, degradation and low reproducibility. Organic single crystals overcame most of the major limitations inherent to thin film-based detectors.
In this experimental work, a starting plethora of commercially available compounds has been crystallized and evaluated in terms of both overall crystallizability and applicability as direct X-ray detectors. This first step of work allow to select only those structures capable to provide single-crystals with good morphological properties and electronic properties suitable for X-ray detections.
A careful screening of some thermodynamic variables affecting the growth has been carried out and the obtained results suggest applicability of the present approach to achieve the control of size, quality and crystal habit. Indeed, single crystals with dimensional and morphological properties suitable to the application as X-ray detector have been prepared.
Single-crystals have been physically attached to Au electrodes deposited on a thin film of polyethylennaphthalate – via the functionalization of the electrode with different self-assembled monolayers (SAMs), chemically and structurally similar to the molecule constituting the selected crystal. In particular, two of the explored SAMs showed very promising results in the first qualitative adhesion tests.
