Improved Sensitivity of Indirect Organic X-ray Detector Using Ag Nanoparticles Blended in Bulk-Heterojunction Active Layer

Abstract

Blending effect of Ag nanoparticles (NPs) in bulk-heterojunction P3HT:PC70BM layer was studied to improve the sensitivity of indirect X-ray detector. Scintillator-decoupled detectors with different contents (1, 3, 5 and 7 wt%) of Ag NPs were fabricated and tested using a solar simulator. Compared with the detector having pristine P3HT:PC70BM layer, the detector with 3 wt% Ag NPs blended in the P3HT:PC70BM layer showed 26% higher PCE and 19% higher Jsc. CsI(Tl) scintillator-coupled detectors were then tested under irradiation of X-ray source. The detector with 3 wt% Ag NPs-blended P3HT:PC70BM layer showed the highest CCD of 350.51 nA/cm2 and the highest sensitivity of 2.20 mA/Gy · cm2. At optimal Ag NPs blending condition, Ag NPs in the P3HT:PC70BM layer can enhance charge-generation by improving absorption of visible-photons and charge-extraction by improving carrier-mobility while lowering resistance.