Nanda developed a UV single photon detector

It is understood that the UV single-photon detector developed by the NTU research team, based on silicon carbide semiconductor chip technology, can sensitively capture ultraviolet single photon and break the bottleneck that used to rely on ultra-low temperature conditions.

At the same time, the detector has significant cost advantages and is expected to be widely promoted to civilian use. At present, part of the research results of the NTU research team in this field has begun to enter the stage of industrialization.

A burning candle can emit more than 100 billion photons in 1 second. Detecting a single ultraviolet photon with such small energy has always been a technical problem in the world. Recently, the research team headed by Professor Lu Hai from the School of Electronic Science and Engineering at Nanjing University has recently made a breakthrough. He first developed a super-sensitivity solid-state UV single photon detector, making China the second country after the United States to master this. The core technology country.

"In nature, ultraviolet light with a wavelength of less than 280 nm is almost zero, so we detect it is equivalent to detecting light in a dark room, as long as a small spot is found to be the target." Luhai said that can detect ultraviolet radiation below 400 nm The UV detector is a key component urgently needed in the fields of flame detection, environmental monitoring, biomedicine, and space science. It is also a key technology related to national security and can be used to detect marine oil pollution and satellite remote sensing monitoring of haze.

Photons are the smallest energy quantum of light, and they are also the smallest transmission unit of light as an information carrier. Of the over 100 billion photons emitted from a candle in 1 second, assuming that the UV photon only accounts for one ten-thousandth of an inch, a lens with an area of ​​1 square centimeter is 1 kilometer away without considering flight loss at all. Only *** to 1000 UV photons in seconds. The single-photon detectors designed to capture these “little guys” have always been the focus of research and competition in countries around the world.

For example, Lu Hai said that there are fingerprint-like special ultraviolet spectral components in the missile's flying tail flame, but the farther the distance is, the weaker the ultraviolet light that can be transmitted is. The use of ultra-sensitive UV single photon detectors makes it possible to detect and discern missiles over thousands of kilometers away, providing valuable time for countering or avoiding. Previously, only three U.S. units, Rutgers University, Virginia University, and General Electric R&D Center, successfully developed silicon carbide single photon detectors. After this breakthrough, the NTU research team became the fourth.

The UV single photon detector developed by NTU's research team, based on silicon carbide semiconductor chip technology, can sensitively capture UV single photons and break the bottleneck that used to rely on ultra-low temperature conditions. “Our detector can still work normally at 150°C. This is because any single-photon detection technology could not be achieved.” said Lu Hai. This breakthrough has also aroused international concern, and the special long article of the “Semiconductor Today” magazine in Europe reported the results of this research.

At the same time, the detector has significant cost advantages and is expected to be widely used in civilian applications. For example, when corona and pollution flash occur on high-voltage transmission lines and high-speed rail power supply lines, remote detection and positioning can be used. “Currently, vacuum ultraviolet phototransistors for ultraviolet fire alarms have a high overall cost.” Luhai took out a stud-sized device and said that in the future, with such a small single photon detector, not only is the cost less expensive, but also explosion-proof. Longer service life.

Right now, part of the research results of the NTU research team in this field has begun to enter the stage of industrialization. Excessive ultraviolet radiation can easily cause skin cancer. Samsung's Note4 mobile phone, which was recently released by Samsung, is equipped with a miniature UV sensor and is popular with consumers.

The NTU research team is working with Huawei's patch-encapsulated UV detectors, which are smaller than rice grains and will also be installed in mobile phones or smart wristbands. With it, users can detect the UV intensity of their environment at any time. Timely protection.