A research team led by Professor Zhang Zhiyong at Peking University has developed groundbreaking technology that allows for the detection of extremely faint starlight using short-wave infrared (SWIR) sensors.

Their innovative device, a heterojunction-gated field-effect transistor (HGFET), achieves unprecedented sensitivity, making it capable of capturing even the weakest infrared radiation.

The findings were recently published in the journal Advanced Materials.

Detecting weak infrared signals is crucial for applications like starlight observation and advanced imaging systems.

However, most existing SWIR detectors struggle to pick up ultraweak signals due to their limited ability to amplify them.

To overcome this limitation, Professor Zhang’s team created the HGFET, which offers ultra-high sensitivity and low noise, thanks to an innovative design that separates optical and electrical processes.

The HGFET consists of two advanced components:

1. Colloidal Quantum Dot (CQD)-based p-i-n heterojunction: This part of the device captures and converts light signals into electrical ones with high efficiency.
2. Carbon Nanotube (CNT) Field-Effect Transistor: This amplifies the signals while keeping noise to a minimum, ensuring clarity and precision.

This unique combination allows the HGFET to detect faint infrared light levels as low as 0.46 nanowatts per square centimeter.

To put this into perspective, the device has a specific detectivity (a measure of sensitivity) above 10¹⁴ Jones at a wavelength of 1300 nanometers—far exceeding the capabilities of existing commercial SWIR detectors.

It also boasts a maximum gain-bandwidth product of 69.2 terahertz, a key factor in processing weak signals rapidly.

Thanks to its high sensitivity, the HGFET is capable of detecting starlight, which opens new possibilities for applications in astronomy, space exploration, and high-performance imaging.

This technology could allow scientists to observe celestial objects more clearly or even create more advanced night vision systems.

“Our device bridges the gap in detecting extremely weak infrared radiation,” said the team, emphasizing the transformative potential of this new approach.

The HGFET’s superior performance compared to current detectors marks a significant step forward in SWIR detection technology. With further development, it could revolutionize fields ranging from space research to imaging in challenging low-light environments, offering a new way to “see” the universe.

Source: Peking University.