New type of "dynamic static dual sensing" charge coupled phototransistor

With the development of cutting-edge technologies such as automatic guidance and embodied intelligence, machine vision has put forward higher requirements for image acquisition, requiring precise recording of static images and the ability to sensitively capture dynamic changes in the scene. The existing dynamic and active pixel sensor technology integrates two functions: dynamic event detection and grayscale image acquisition. However, each pixel usually requires dozens of transistors and circuit components, and the structure is complex, the power consumption is high, the integration difficulty is high, and it also faces engineering challenges such as high-speed clock synchronization.

In response to the above issues, the team led by Sun Dongming, a researcher at the Institute of Metals, Chinese Academy of Sciences, has proposed a new "dynamic static dual sensing" charge coupled phototransistor. This type of transistor only requires one device unit to synchronously achieve dynamic and static image information acquisition. The related research results, titled A charge coupled phototransistor enabling synchronous dynamic and static image detection, were published in Advanced Materials.

This study designed a gate structure of "upper and lower dual photosensitive capacitors". The upper gate shields electrons through a thicker dielectric layer, causing stable current changes in the device for capturing grayscale images; The lower gate uses a thinner dielectric layer to allow electrons to tunnel and form transient current pulses, specifically designed to capture dynamic events. Through this unique charge coupled grating mechanism, independent response of static images and dynamic events has been achieved within a transistor. Tests have shown that the dynamic range of the device reaches 120 dB, the response speed is as fast as 15 μ s, and the power consumption is only 10 pW, which is only one thousandth of traditional dynamic and active pixel sensor devices.

The above achievements have reduced power consumption, facilitated large-scale integration, and fundamentally solved the problem of high-speed clock synchronization. At the same time, this invention can be made using two-dimensional materials or one-dimensional carbon nanotubes, with good material universality.

Structure and characterization of charge coupled phototransistors

The research work was supported by the National Natural Science Foundation of China, the National Key Research and Development Program, and related projects of the Chinese Academy of Sciences.

Source: opticsky