Improvement of the Sensitivity of Indirect Organic X-ray Detector Using Conductivity Change of Hole Transport Layer

Abstract

In this paper, we report on our study of the sensitivity of an indirect-type organic X-ray detector, which depends on the conductivity of the hole-transport layer composed of PEDOT:PSS. The polar solvent, dimethylformamide (DMF), was mixed with the PEDOT:PSS solution to improve the conductivity of the HTL. When the DMF was added to the PEDOT:PSS solution, the conductive PEDOT fragments distributed more uniformly because of the high dipole moment of the DMF. In order to find the optimal process condition, the blending ratio of DMF and the baking condition of the PEDOT:PSS layer were examined. The detector with the PEDOT:PSS layer fabricated with 50 wt% DMF added and 160 °C baking for 30 min had the highest sensitivity, of 1.988 mA/Gy · cm2, which was 61.23% higher than the sensitivity of the detector with the pristine PEDOT:PSS layer.