Latest advancements in bandgap engineered MCT for HOT MW and low dark current arrays at Leonardo UK

For more than 20 years, Leonardo UK (LEUK) has been manufacturing MCT-based IR detectors using a unique MetalOrganic Vapor-Phase Epitaxy (MOVPE) growth process. One advantage of this approach is that it enables the use of sophisticated bandgap engineering techniques to optimize the MCT heterostructure for high-performance, low-dark current operation. These optimizations have led to the development at LEUK of high-performance HOT MWIR and low-dark current LWIR MCT arrays. HOT MW arrays (640x512/16 μm) demonstrated a mean Noise Equivalent Temperature Difference (NETD) of 15.8 mK with near Gaussian histograms and an operability of >99.99% at 140 K with F/4 optics. The same array demonstrated an average Residual Spatial Noise (RSN) of 7.9 mK at 150 K, marking a significant improvement against the previous iteration. LWIR arrays were developed for earth observation applications in which dark current, rather than electro-optical performance, is the key performance metric. Bandgap engineering techniques have been applied in the development of a LWIR (1280x1024/12 μm) array with a 50% cut-off at 11.7 μm. This array demonstrated near Rule 07 dark current down to 60 K, at which point the NETD was 32.7 mK. Keywords: