Breakthrough in infrared imaging technology opens up applications in the biomedical field

2024-01-08

Infrared radiation is one of the widespread radiation in nature, and as long as the temperature of an object is above zero degrees (-273.15 ℃), it will continuously emit infrared signals outward. The electromagnetic wave length of infrared radiation ranges from 0.75 to 1000 μ Between m, between 0.75 and 3 μ The infrared within the range of m is called near-infrared or shortwave infrared. Near infrared is an important component of electromagnetic spectrum, widely used in various fields such as aerospace, optical communication, atmospheric detection, and biological detection.

Near infrared imaging is the use of shortwave infrared radiation commonly present in the target reflection environment for imaging, rather than the infrared radiation emitted by the target itself. The image formed by near-infrared light is similar to visible light imaging seen by the naked eye, but due to the need for infrared photodetectors and readout circuits to be integrated into imaging devices, and the complexity of the integration process, near-infrared light imaging has not been greatly developed.

Recently, researchers from the School of Materials Science and Technology of Shanghai University of Science and Technology have developed a new type of infrared upconverter device based on colloidal quantum dot materials, which greatly improves the detection rate and reduces the cost of detectors. Moreover, this type of infrared upconverter device also has good application prospects in the fields of biological imaging and wearable electronics.

The infrared upconverter device consists of an infrared photodetector and a light-emitting diode. Researchers use colloidal quantum dot materials to create infrared absorption layers and visible light emission layers for conversion devices. Colloidal quantum dot materials can be prepared by solution method. Compared with the traditional vacuum deposition method for conversion devices, the solution method not only has low cost but also a simple preparation method.

In response to the problem of low overall photon to photon conversion efficiency in traditional conversion devices, the research team introduced silver nanoparticles into the zinc oxide electron transport layer of the detector, resulting in an external quantum efficiency of 8000% and a detection rate of 6% for colloidal quantum dot infrared detectors × 1012 Jones, response speed in milliseconds. After being combined with colloidal quantum dot light-emitting diodes, the photon conversion efficiency of the infrared upconversion device reaches 6.5%. These data are among the top in similar products.

When exploring the application field of this device, researchers found that using an infrared upconverter device, infrared irradiation can distinguish between normal and cancerous tissues in mouse breast tissue. This means that infrared upconverter devices can be used for infrared imaging in the biomedical field, and infrared, as a harmless radiation to the human body, will open up broad application markets in the field of biological imaging. At the same time, researchers have successfully developed flexible infrared upconverter components that can be applied to wearable electronic devices. The combination of new infrared imaging technology and wearable electronic devices may bring significant changes to the medical device industry.

Source: Science and Technology Daily

Editor's comment: Infrared imaging technology is a promising high-tech field. In nature, all objects can emit infrared radiation, and using a detector to measure the infrared difference between the target itself and the background can obtain infrared images formed by different thermal infrared rays. It is believed that with the improvement and updating of various equipment on the infrared converter, near-infrared imaging technology can be better applied and contribute more to human production and life

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