Starlight detection achieved with advanced short-wave infrared sensor

Starlight detection achieved with advanced short-wave infrared sensor
by Simon Mansfield
Sydney, Australia (SPX) Dec 27, 2024

Researchers at Peking University, led by Prof. Zhang Zhiyong, have developed a groundbreaking heterojunction-gated field-effect transistor (HGFET) capable of detecting faint starlight through highly sensitive short-wave infrared (SWIR) detection. The device, featuring a specific detectivity above 1014 Jones at 1300 nm, represents a major step forward in optoelectronic technology. The findings were recently published in Advanced Materials under the title "Opto-Electrical Decoupled Phototransistor for Starlight Detection."

Short-wave infrared detectors play a critical role in capturing weak radiation levels, typically below 10-8 W-Sr-1-cm-2-um-1, for applications such as passive night vision imaging. Conventional SWIR technologies, primarily based on epitaxial photodiodes, often fall short in detecting ultraweak infrared signals due to the absence of inherent gain. Addressing this limitation, the Peking University research team introduced the HGFET, which leverages an innovative opto-electric decoupling mechanism to achieve exceptional photogain with minimal noise amplification.

The novel HGFET integrates a colloidal quantum dot (CQD)-based p-i-n heterojunction with a carbon nanotube (CNT) field-effect transistor. This unique architecture enables the device to achieve unparalleled sensitivity, recording a maximum gain-bandwidth product of 69.2 THz and detecting weak infrared signals as low as 0.46 nW/cm. Comparative testing has demonstrated its superior performance compared to commercial SWIR detectors, establishing its capability for starlight vision and other advanced imaging applications.

In addition to its performance, the HGFET fabrication process is fully compatible with CMOS readout integrated circuits, making it a versatile platform for high-end passive image sensors. This compatibility facilitates the development of optoelectronic circuits with high resolution and sensitivity at a lower cost.

The research, supported by the Natural Science Foundation of China and Peking Nanofab Laboratory, holds significant potential for advancing monolithic integration systems and next-generation optoelectronic devices. Zhou Shaoyuan, a doctoral student at Peking University, served as the paper's first author, with Wang Ying and Zhang Zhiyong as co-corresponding authors.

Research Report:Opto-Electrical Decoupled Phototransistor for Starlight Detection