Scientists create a UV detector based on nanocrystals synthesized via ion implantation

August 7, 2018, Lobachevsky University
Schematic representation of the photodetector with Ga2O3 nanocrystals encapsulated in Al2O3 matrix (a), TEM image of the implanted Al2O3 film containing Ga2O3 nanocrystals (b), and responsivity spectra of photodetectors measured at different voltages (c). Credit: Lobachevsky University

Scientists at the Lobachevsky University have been working for several years to develop solar-blind photodetectors operating in the UV spectral band. In the field of electronic technology, this is an important task, since such devices cut off emission with a wavelength higher than 280 nm, which helps to avoid interference from sunlight and to record UV emission during daylight.

"Due to their high sensitivity to deep UV emission and insensitivity to sunlight, solar-blind photodetectors provide a wide range of important applications, including ozone damage detection, jet engine monitoring and flame detection," says Alexey Mikhaylov, head of the laboratory at the UNN Physics and Technology Research Institute.

The main materials for creating solar-blind photodetectors are wide-gap semiconductors. Nizhny Novgorod scientists, together with Indian colleagues, consider Ga2O3 to be a promising semiconductor with a band gap of 4.4-4.9 eV, which cuts off emission with wavelengths higher than 260-280 nm, and is capable of detecting in the deep ultraviolet range.

The existing methods for Ga2O3 synthesis are quite complicated and incompatible with conventional silicon technologies. Additionally, the layers obtained by such methods often have many defects. The synthesis of Ga2O3 nanocrystals by means of , the basic of modern electronics, opens up new possibilities for creating solar-blind photodetectors.

The spectral dependence of photoresponse for this photodetector demonstrates excellent solar-blind ultraviolet characteristics in the wavelength range of 250-270 nm, it also has a high responsivity of 50 mA/μW. The dark current of the is quite low and amounts to 0.168 mA.

The process of creating such a detector involves the synthesis of Ga2O3 nanocrystals in a Al2O3 film on silicon by ion implantation. The detector obtained by this method has been realized by the scientists for the first time in the world.

Thus, the joint work of the international team of researchers from the Lobachevsky University, the Indian Institute of Technology Jodhpur and the Indian Institute of Technology Ropar has demonstrated the possibility of manufacturing photodetectors that cut off solar radiation (solar-blind photodetectors) capable of working in the deep ultraviolet region and possessing the characteristics that are not inferior to the existing analogs."By producing such photodetectors with the help of ion implantation, it will be possible to use the existing silicon technologies and to adapt them to the manufacture of new-generation devices," concludes Alexey Mikhaylov.

Explore further: UV narrow-band photodetector based on indium oxide nanocrystals

More information: Saravanan Rajamani et al, Enhanced Solar-Blind Photodetection Performance of Encapsulated Ga2O3 Nanocrystals in Al2O3 Matrix, IEEE Sensors Journal (2018). DOI: 10.1109/JSEN.2018.2821562

Related Stories

UV light improves smartphone cameras

October 24, 2016

Photodetectors, which are used in a wide range of systems and devices from smartphones to space stations, are typically only sensitive to light within a certain narrow bandwidth. This presents numerous challenges to product ...

Recommended for you

Solving mazes with single-molecule DNA navigators

November 16, 2018

The field of intelligent nanorobotics is based on the great promise of molecular devices with information processing capabilities. In a new study that supports the trend of DNA-based information carriers, scientists have ...

A way to make batteries almost any shape desired

November 16, 2018

A team of researchers from Korea Advanced Institute of Science and Technology, Harvard University and Korea Research Institute of Chemical Technology has developed a way to make batteries in almost any shape that can be imagined. ...

Graphene flickers at 400Hz in 2500ppi displays

November 16, 2018

With virtual reality (VR) sizzling in every electronic fair, there is a need for displays with higher resolution, frame rates and power efficiency. Now, a joint collaboration of researchers from SCALE Nanotech, Graphenea ...

'Smart skin' simplifies spotting strain in structures

November 15, 2018

Thanks to one peculiar characteristic of carbon nanotubes, engineers will soon be able to measure the accumulated strain in an airplane, a bridge or a pipeline – or just about anything – over the entire surface or down ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.