Abstract
To improve sensitivity of the indirect-type organic detector, polycarbazole copolymer poly [N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) was examined as p-type material instead of the common poly (3-hexylthiophene) (P3HT). The fullerene derivative [6,6]-phenyl-C-71-butyric acid methyl ester (PC70BM) was selected as an n-type material. To find optimal process condition, blending ratio and spin-coating condition of PCDTBT:PC70BM active layer were examined. The organic detector at the condition of PCDTBT:PC70BM = 1:4 blending ratio and 1500 rpm spin-rate revealed highest sensitivity of 1.69 mA/Gy⋅cm2 and highest power conversion efficiency (PCE) of 4.83%. Compare to the common P3HT:PC70BM detector, it revealed 39.7% enhancement of sensitivity and 67.1% enhancement of PCE.