Semiconducting Polymer Photodetectors with Electron and Hole Blocking Layers: High Detectivity in the Near-Infrared

Xiong Gong,Alan J Heeger,Michelle Liu,Ming-Hong Tong,Alex Jen,Sung Heum Park

doi:10.3390/s100706488

Abstract

Sensing from the ultraviolet-visible to the infrared is critical for a variety of industrial and scientific applications. Photodetectors with broad spectral response, from 300 nm to 1,100 nm, were fabricated using a narrow-band gap semiconducting polymer blended with a fullerene derivative. By using both an electron-blocking layer and a hole-blocking layer, the polymer photodetectors, operating at room temperature, exhibited calculated detectivities greater than 1013 cm Hz1/2/W over entire spectral range with linear dynamic range approximately 130 dB. The performance is comparable to or even better than Si photodetectors.

Highlights

Sensing from the ultraviolet (UV)-visible to the infrared is critical for a variety of industrial and scientific applications, including image sensing, communications, environmental monitoring, remote control, day- and night-time surveillance and chemical/biological sensing [1,2,3]
For Polymer photodetectors (PPDs) A: Indium tin oxide (ITO)/PEDOT/PCPDTBT:PC70BM/Al, a ~200 nm Al layer was thermally deposited on top of the bulk heretojunction (BHJ)
The dark currents observed from PPD B are more than 2 orders of magnitude smaller than that from PPD A; the dark currents observed from PPD C are more than 10 times smaller than that from PPD B. These results indicate that the thin C60 and PS-TPD-PFCB buffer layers are important for minimizing the dark currents generated withinfrom the PCPDTBT:PCBM PC70BM BHJ structure

Summary

Introduction

Sensing from the ultraviolet (UV)-visible to the infrared is critical for a variety of industrial and scientific applications, including image sensing, communications, environmental monitoring, remote control, day- and night-time surveillance and chemical/biological sensing [1,2,3]. For PPD A: ITO/PEDOT/PCPDTBT:PC70BM/Al, a ~200 nm Al layer was thermally deposited on top of the BHJ For PPD B: ITO/PEDOT/PCPDTBT:PC70BM/C60/Al, a ~30 nm

Results

Conclusion