Speaker
Description
Organic photodetectors (OPDs) are appealing candidates for medical dosimetry because of to their tissue equivalence. However, their low detection efficiency for high-energy photons hinders their use in radiology. In this work, we investigate the use of lead phthalocyanine (PbPc), a small-molecule semiconductor with optical absorption in the visible and near-infrared (NIR). The central heavy atom in PbPC can enhance X-ray attenuation when the material is used in thin-film OPDs.
The study initially focuses on interface engineering to optimize extraction and reduce recombination. The influence of different hole transport layers (HTLs), as well as their combination in bilayers, was evaluated. Injection layers such as PEDOT:PSS and molybdenum oxide ($MoO_{3}$) were also investigated, and found to reduce dark currents and overall performance parameters.
The effect of the choice of electron transport layers (ETLs) was studied as well. Materials such as $C_{60}$, BCP, $SnO_x$ were evaluated as top ETLs, leading to a further improvement in efficiency. In this work we will discuss also the difference between bilayer and bulk heterojunctions (BHJ), and their implication in the design of efficient optical sensors.