Organic Photodiode with High Infrared Light Sensitivity Based on Tin Phthalocyanine/C60 Bulk Heterojunction and Optical Interference Effect

概要

論文の詳細を見る
We demonstrated an organic near-infrared (NIR) photodiode on the basis of the bulk heterojunction (BHJ) structure by using tin phthalocyanine (SnPc) and C60 fullerene with a high incident photon--electron conversion efficiency (IPCE) of 50% at a wavelength of 750 nm. The cell showed optical responses to about 1000 nm and had a specific detectivity D^{*} of 1.59 \times 10^{11} cm Hz1/2/W. The SnPc:C60 ratio in the BHJ layer influenced the optical response. Higher ratios enhanced NIR sensitivity but reduced the peak IPCE; the optimal ratio was 3:1. The optical interference of directly incident light and light reflected from an Al electrode was also examined to enhance the IPCE at longer wavelengths. With a 90-nm-thick C60 layer, the first antinode of the standing wave at a wavelength of 750 nm was located at the BHJ layer; this layer enhanced the IPCE at 700 and 800 nm but reduced it at 400 nm.
2012-03-25