Single-chip, Mid-Infrared Array for Room Temperature Video Rate Imaging

The need for energy efficiency and lower emissions from industrial plant and infrastructure is driving research into novel sensor technologies, especially those that allow observing and measuring greenhouse gases such as CO2. CO2 emissions can be captured using mid-infrared imagers, but at present these are based on hybrid technologies that need expensive manufacturing, that require cooling and are prone to failure. The high price tag prevents a wider diffusion of mid-infrared imagers, hence their use for many low-cost and large-volume applications. Here we report a monolithic III-V technology that integrates GaAs transistors with an InSb photodiode array. The monolithic material system reduces costs and provides an excellent platform for sensor system-on-chip. We present a focal plane array imaging technology operating at room temperature in the 3 to 6 µm wavelength range that will address the need for identification and measurement of a range of industrially important gases.