Samsung Advanced Institute of Technology

    Photodetectors that convert photons to electrical signals are the foundation of present-day light detection technologies. Depending on the absorption spectrum of the active material, photodetectors are classified into different types, e.g., X-ray detectors, visible detectors and infrared (IR) detectors. 

    This review is written to introduce infrared photon detectors based on solution-processable semiconductors, as opposed to infrared thermal detectors.  We explore the recent advances in solution processed IR detectors in terms of functional materials, device physics and novel applications. Typically, there are three types of photon detector structures: photodiode, photoconductor, and phototransistor. These three types of detectors have their own characteristic features in terms of photosensitivity, response speed, noise level, and device size. Deliberate device configurations can enable new sensing functions, such as upconversion detectors for IR light sensing and imaging, and also multispectral detection and  imaging. As compared to prior reviews, this work focuses on IR detection by using disordered semiconductors, including organics, CQDs and low dimensional materials, to explain how device behavior is different from conventional inorganics.