Novel photodetectors based on nanomaterials: devices and applications

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The main objectives of this project are to:

• Investigate novel photodetectors for the mid-to long-wave infrared spectral range based on new nanomaterials and nano-optics.
• Develop new imaging and spectroscopy systems by combining these devices with spatial light modulators.

The details

Recent advances in nanomaterials present opportunities for novel photodetector devices and imaging and spectroscopy systems. Much of the previous work in this field has been in the visible and near-infrared spectral bands. The mid-to long-wave infrared spectral range has been far less explored, despite the abundant applications in this wavelength range. Here, we will investigate novel photodetectors for this spectral range based on new nanomaterials (primarily by SJTU) and nano-optics (primarily at UoM). We will also develop new imaging and spectroscopy systems by combining these devices with spatial light modulators.

We propose a research program on the development of IR photodetectors based on nano-optics and ultra-thin materials. For the latter, we will investigate what are known as two-dimensional (2D) materials. Such photodetector devices present the opportunity for room temperature operation.

Conventional infrared photodetectors generally require cooling. This is because, by definition, infrared radiation comprises photons with small energies, generally detected by semiconductors with small bandgaps. In such materials, carriers are thermally generated at high rates at room temperature, degrading the signal-to-noise ratio (SNR). Cooling (e.g. by liquid nitrogen) mitigates this but adds substantially to size, weight, power consumption and cost.

We propose to develop new types of photodetectors that combine semiconductors with small bandgaps with 2D materials and with nano-optical structures. These will operate using a principle termed “photogating”.  Light will be absorbed by the small bandgap semiconductor material, resulting in the generation of electron-hole pairs. These carriers will in turn modify the conductance of the 2D material. It will then be possible to detect infrared radiation by monitoring the resistance of the 2D material.

This project will be complemented by the related project on Mid-infrared photodetectors based on atomically thin 2D materials. The collaboration will ensure the successful completion of both projects.

The graduate researcher on this project is: Seyed Saleh Mousavi Khaleghi

Supervision team

University of Melbourne supervisor:
Professor Kenneth Crozier

Shanghai Jiao Tong University supervisor:
PAssociate Professor Yaping Dan