From starlight to visibility: researchers develop shortwave infrared technology that enables detection of starlight

Professor Zhang Zhiyong’s team at Peking University has developed a heterojunction-gate field-effect transistor (HGFET) that achieves high sensitivity in shortwave infrared detection, recording a specific detection power of over 1014 Jones at 1300nm, and detecting starlight. became possible. Their work was recently published in the journal Advanced Materials under the title “Optoelectrically isolated phototransistors for starlight detection.”

Highly sensitive shortwave infrared (SWIR) detectors are essential for detecting weak radiation (typically less than 10−8 W·Sr−1·cm−2·μm−1) in high-end passive image sensors. However, mainstream SWIR detection based on epitaxial photodiodes cannot effectively detect ultra-weak infrared radiation due to the lack of inherent gain.

To fill this gap, researchers and collaborators from Peking University’s School of Electronics have developed a heterojunction-gated field-effect transistor (HGFET) that achieves ultra-high optical gain and very low noise in the short-wavelength infrared (SWIR) region. Announced. Designed with comprehensive photoelectric decoupling mechanism.

The research team developed an HGFET consisting of a colloidal quantum dot (CQD)-based pin heterojunction and a carbon nanotube (CNT) field-effect transistor. It detects and amplifies SWIR signals significantly with high inherent gain while minimizing noise amplification. We recorded a specific detection rate of over 1014 Jones at 1300 nm and a maximum gain-bandwidth product of 69.2 THz.

Direct comparison tests have shown that the HGFET is capable of detecting weak infrared radiation at the 0.46 nW cm-2 level, making this detector much more sensitive than commercially reported SWIR detectors, especially It allows for detection and vision of starlight.