Optical up-conversion devices based on organic and inorganic quantum dot materials

Infrared (IR) to visible up-conversion devices made by incorporating IR detectors with visible emitting units can directly convert IR light into visible light. They are currently of great significance in engineering monitoring, medical imaging and night vision imaging applications. Up-conversion devices without complex readout circuits can be fabricated entirely using organic or inorganic materials. Additionally, the construction of organic/inorganic hybrid devices has also been accomplished. Strong absorption of IR light and efficient emission of visible light can be achieved by novel IR up-conversion devices based on organic emitting units and inorganic quantum dot photodetectors. Organic/inorganic up-conversion devices act as an effective substitute for the previous infrared imagers that consist of semiconductor photodiode arrays connected with readout circuits. In this review, which is the first of its kind, the characteristics and design principles of up-conversion devices are described. The merits and defects of up-conversion devices with all kinds of semiconductor materials are analysed in a critical way. Finally, the challenges and opportunities encountered by these materials and devices are summarized. Infrared (IR) to visible up-conversion devices made by incorporating IR detectors with visible emitting units are able to directly convert IR light into visible light.