Time-Resolved Response of Polymer Bulk-Heterojunction Photodetectors

We have fabricated a polymer bulk-heterojunction photodetector from a (1:0.7) blend solution of poly(3-hexyl-thiophene) (P3HT) and 1-(3-methoxy-carbonyl)propyl-1-phenyl-(6,6)C-61 (PCBM) in o-dichlorobenzene. Absorption spectrum, external quantum efficiency and current-voltage (I-V) curves, both in dark condition and under illumination of a narrowband green light-emitting diode (green-LED) with lambda(em,peak) center at 525 nm, were measured to characterize the photodiode behavior. Moreover, the time-resolved response under the green-LED stimulus modulated at 200 KHz has been measured. This result suggests the application of our device as organic photodetector for all-organic optical data link in low-cost plastic-optical-fiber-based systems.