posted on 2023-10-10, 16:07authored byMeng Xu, Long Zhou, Sixin Chen, Yang Chen, Pei Yuan, Wanqi Jie, Menghua Zhu
Organic semiconducting materials
featuring nontoxicity, tissue-equivalence,
and compatibility with flexible substrates are attracting wide attention
for potential applications in the areas of OLEDs, plastic photovoltaics,
and biochemical detectors. However, the relation between anisotropic
electronic transport properties and radiation performance are still
confused. Here, we report two kinds of architectures (ab-direction and c-direction) based on 4-hydroxycyanobenzene
(4HCB, C7H5NO) single crystals, grown by a solvent
evaporation method. The low symmetry of organic molecules leads to
anisotropically packed crystal structures, and the direction of the
strongest π-orbitals overlap coincides with the ab-direction of the highest carrier mobility (7.67 cm2·V–1·s–1) and hole mobility-lifetime
products (2.25 × 10–4 cm2·V–1). Simultaneously, the X-ray detection performances
of the 4HCB detectors along different directions are measured with
a detection limit as low as 0.19 μGyair·s–1 and sensitivity of 21.87 μC·Gyair–1·cm–2 (10.99 μC·Gyair–1·cm–2) along
the c-direction (ab-plane). This
work displays the impact of anisotropic structure properties on the
radiation detection performance and provides a certain theoretical
support on organic single crystal semiconductor devices.