Mid-Infrared (IR) sensing and imaging have widespread military and industrial applications (see table on the right). Many applications require high performance and affordable solutions. The mid-IR detector system thus needs to be compact, portable and cost-effective, favoring uncooled midIR detectors without a bulky and expensive cryocooler. To date, uncooled, lowcost Pb-salt (PbS and PbSe) photoconductive (PC) detectors remain the choice for many applications in the 1-5 µm mid-IR spectral range. The key figure of merit used to characterize photodetector is called specific detectivity, or D*. The higher the D*, the smaller temperature difference from the target object a detector can tell, making the detector more sensitive. Detector sensing or imaging system that has higher D* will have competitive advantages over its competitors. Currently about 20 companies are selling such detector products. The table on next page lists major companies involved in Pb-salt detectors. They are all striking to achieve high D* value.

Markets for mid IR sensors are estimated at $70.2 million in 2008 and are anticipated to reach $865.4 million by 2015.” (Source: Global Information, Inc). Data on the market share of uncooled Pb-salt PC detector is not available. The list on the right provides information on world-wide companies that are involved in Pbsalt PC detectors. The commercial and dual use (excluding military) world-wide market for infrared imaging equipment was estimated well over 2 billion dollars. Currently Pb-salt detectors are not the major player on the imaging market. OU group’s recent breakthrough in IV-VI lead salt PC detectors could lead to new and better understanding of critical issues in Pb-salt materials, and could help introduce process they developed to other Pb-salt devices such as photovoltaic detectors and therefore open doors for Pb-salt detectors to gain market share in midwave/long-wave imaging applications.