Near infrared photo-detector using self-assembled formation of organic crystalline nanopillar arrays

We proposed a near infrared photo-detector (NIR-PD) using self-assembled formation of organic crystalline arrays, which were formed on an n-type silicon (n-Si) substrate and covered with an Au film. These structures act as antennas for near infrared (NIR) light, resulting in an enhancement of the light absorption on the Au film. The NIR-PDs thus have higher photo-responsivity compared with that of an Au/n-Si typed Schottky diodes, which was fabricated as a reference. In this paper, the fabrication process of the NIR-PDs and the estimation results of photo-responsivity were described. The maximum responsivity to NIR light (wavelength = 1.2 μm) was 1.79 mA/W without applying forward bias. This value is 10 times larger than the responsivity of the Au/n-Si typed Schottky diode as a reference.