NEXT WAVE PHOTODETECTOR USING GRAPHENE

To develop a new type of photodetector, Researchers from UCLA are using graphene which has superior sensing and imaging capabilities and is able to work with several different types of light. Due to the ability to absorb energy from a broad swath of the electromagnetic spectrum Graphene is able to detect photons —from ultraviolet light to visible light to the infrared and microwave bands.
The researchers placed strips of graphene to create the improved photodetector over a silicon dioxide layer, which covers a base of silicon. They then created a series of comb-like nanoscale patterns comprised of gold with about 100 nanometer wide teeth. The graphene can catch the incoming photons and convert them into an electrical signal. The gold comb-shaped nanopatterns transfer the information into a processor and the processor even under low-light conditions produces a comparably high-quality image.
As per emih Cakmakyapan, a UCLA postdoctoral scholar and the lead author of the study,“This design efficiently produces an electrical signal which follows ultrafast and subtle variations in the light's intensity over the entire spectral range, from visible to infrared.”In different imaging devices, Different photodetectors sense different parts of the light spectrum and create images from the patterns. To sense thermal radiation invisible to the naked eye at night, Photodetectors can be used or in cameras that can identify chemicals in the environment by how they reflect light.
Depending on their operating speed, their sensitivity to lower levels of light and how much of the spectrum they can sense.

The photodetectors can sense different types of light largely which It has proven difficult for engineers to improve a photodetector’s capability in one specific area without diminishing at least one of the other two areas.
The new and improved photodetector represents an improvement in all three areas as it operates across a broad range of light, processes images more quickly and is more sensitive to low levels of light than current photodetectors. Our photodetector could extend the potential uses of photodetectors in imaging and sensing systems,” Mona Jarrahi, a professor of electrical and computer engineering, who led the study, said in a statement. “It could be used in environmental sensing technologies to more accurately identify the concentration of pollutants.”It could also dramatically improve thermal imaging in night vision or in medical diagnosis applications where precise differences in temperatures can give doctors a lot of information on their patients.