Sensor breakthrough clears path for photography in dim light
25 June 2013
Cameras fitted with a new graphene based sensor will soon be able to take clear and sharp photos in dim conditions, thanks to a new image sensor developed by researchers at Nanyang Technological University (NTU) in Singapore.
NTU’s Professor Wang Qijie shows the thin and flexible photodetector which he and his team have fabricated from pure graphene
The researchers believe it to be the first sensor able to detect broad spectrum light, from the visible to mid-infrared, with such sensitivity, opening up opportunities for use in all types of cameras, including infrared cameras, traffic speed cameras, satellite imaging and more.
Not only is the graphene sensor 1,000 times more sensitive to light than the imaging sensors found in today’s cameras, it also uses ten times less energy as it operates at a lower voltage. And when in mass production, it is estimated that these sesnsors will be at least five times less costly to manufacture.
The inventor of the new graphene imaging sensor, NTU’s Professor Wang Qijie, believes it to be the first time that a broad-spectrum, highly photo-sensitive sensor has been developed using pure graphene. His idea was to create nanostructures on graphene that are able to ‘trap’ light-generated electrons for a much longer time, resulting in a stronger electric signal.
Trapping the electrons in the graphene nanostructure is the key to achieving the sensor’s high sensitivity, which Professor Wang Qijie claims makes it far more effective than CMOS or CCD imaging sensors. Essentially, the stronger the electric signals generated, the clearer and sharper are the resultant images.
“We have shown that it is now possible to create cheap, sensitive and flexible photo sensors from graphene alone,” says Professor Qijie. “We expect our innovation will have great impact not only on the consumer imaging industry, but also in satellite imaging and communication industries, as well as mid-infrared applications.
“While designing this sensor, we have kept current manufacturing practices in mind. This means the industry can in principle continue producing camera sensors using the widely used CMOS process.
"Therefore manufacturers can easily replace the current base material of photo sensors with our new nano-structured graphene material.” If adopted, Professor Wang Qijie expects the cost of manufacturing imaging sensors to fall, eventually leading to cheaper cameras with longer battery life.
“The performance of our sensor, such as the response speed, can be further improved through nanostructure engineering of grapheme; preliminary results have already verified the feasibility of our concept,” he adds.
The development has taken Professor Wang Qijie and his team of research fellows and students a total of two years to complete and he has filed a patent through NTU’s Nanyang Innovation and Enterprise Office for his invention. The next step is to work with industry collaborators to take the graphene sensor to market.
Professor Wang Qijie can be contacted: firstname.lastname@example.org