City University of Hong Kong

The Hong Kong Research Institute of Textiles and Apparel Limited

Wei Wang

John Haozhong Xin

Sijie Shao

Huiliang Shen

You Meng

Zhi-Huan Zheng

Pengshan Xie

The large-scale artificial synaptic device arrays based on the organic molecule-nanowire heterojunctions with tunable photoconductivity are proposed and demonstrated. The organic thin films of p-type 2,7-dioctyl[1]benzothieno[3,2-b][1] benzothiophene (C8-BTBT) or n-type phenyl-C61-butyric acid methyl ester (PC61BM) are used to wrap the InGaAs nanowire parallel arrays to configure two different type-I heterojunctions, respectively. Due to the difference in carrier injection, persistent negative photoconductivity (NPC) or positive photoconductivity (PPC) are achieved in these heterojunctions. The irradiation with different wavelengths (solar-blind to visible ranges) can stimulate the heterojunction devices, effectively mimicking the synaptic behaviors with two different photoconductivities. Evidently, these photosynaptic devices are illustrated with retina-like behaviors and capabilities for large-area integration, which reveals their promising potential for artificial visual systems.

Artificial visual systems with tunable photoconductivity based on organic molecule-nanowire heterojunctions

Fast focusing methods and devices for multi-spectral imaging are disclosed. The method comprising selecting one of a plurality of imaging channel as a reference channel, adjusting rotation positions of a stepper motor, calculating focus measures corresponding to all rotation positions of the stepper motor, and obtaining a first distribution curve; in each of the other imaging channels, selecting at least three rotation positions of the stepper motor, matching focus measures at the selected rotation positions with the first distribution curve to obtain a second distribution curve and a offset value between the first distribution curve and the second distribution curve, and calculating a clear focusing position of the imaging channel to be focused according to the offset value; performing a fine-tuning focusing, and thereby obtaining a more precise clear focusing position. A fast focusing for multi-spectral imaging and obtain clear multi-spectral images is obtained.

Fast focusing method and device for multi-spectral imaging

Growing community of inventors

Hong Kong, China

Wei Wang