Silicon based CMOS (Complementary metal-oxide semiconductors) technology are at the basis of many of the electronic devices we widely use today, such as computers, smartphones and digital cameras. To move to a new generation of advanced electronics, most researchers are of the view of the need to integrate CMOS with other semiconductors. As part of this process, technologists from the Institute of Photonic Sciences in Barcelona have successfully integrated graphene into a CMOS integrated circuit.
With the process graphene is deposited onto a surface, then patterned to create the necessary pixel shape. At the end of the process a layer of PbS colloidal quantum dots are added. Quantum dots are very tiny semiconductor particles, only several nanometres in size. They are so small that their optical and electronic properties differ from those of larger particles.
This circuit has led to the development of a high resolution image sensor. When the sensor is used as a digital camera it allows the camera to sense ultraviolet, visible and infrared light at the same time. This essentially allows the camera to ‘see’ most of what is invisible to the human eye, including in situations of near-complete darkness.
Graphene is a single atom thick layer of a from of carbon. The material is transparent, at least as strong as steel, and it possess many remarkable properties, such as being highly conductive of electricity. The many applications of graphene have been widely covered by Digital Journal.
READ MORE: Graphene helps to make nuclear industry ‘greener’
Other applications of the new sensor include microelectronics, sensor arrays and low-power photonics. Each of the developments could lead to a new generation of smartphone cameras, fire control systems, enhanced night vision and surveillance cameras.
The research has been published in the journal Nature Photonics, under the title “Broadband image sensor array based on graphene–CMOS integration.”
