PMSE 150 |
| High performance near-infrared photodetectors are of tremendous importance in scientific and industrial applications. Here we report the first plastic near-infrared photodetector using a new low band gap polymer. By utilizing an ester group modified polythieno[3,4-b]thiophene, we have successfully lowered the highest occupied molecular orbital energy level of the polymer, so that it can match the energy level of (6,6)-phenyl C61-butyric acid methyl ester and has good solubility. When composing the device in a donor-acceptor type energy band structure and operating it in the reverse bias condition (less than 5 V), we show that the photodetector has external quantum efficiency exceeding 38%, bandwidth of 4 MHz and the noise equivalent power of 3.85 × 10-12 W/Hz1/2 at 850 nm. Although these parameters are still inferior to those of commercial silicon detectors, we note that our plastic photodetectors have not been fully optimized and there is still room for better performance. With the promising results demonstrated here, we believe low band gap materials will open up a new perspective in the near-infrared detection. |
|
ICI Student Award Symposium
8:30 AM-11:55 AM, Tuesday, August 21, 2007 Westin Boston Waterfront -- Grand Ballroom D, Oral
Division of Polymeric Materials: Science & Engineering |