Hg based II–VI compounds on non‐standard substrates

Abstract The Army Research Laboratory (ARL) is pursuing scalable infrared (IR) material technologies to meet the growing need for large format arrays. A two pronged approach is being undertaken at ARL using II–VI semiconductor materials. The first encompasses the well developed IR material system HgCdTe but grown on large area, extremely lattice mismatched Si(112) substrates. To overcome the high dislocation density associated with the large mismatch within the as‐grown material, ARL has successfully pursued a postgrowth thermal cycle annealing (TCA) process to reduce the dislocation density by an order of magnitude. Current results show HgCdTe/Si material can consistently be achieved with dislocation density values on the order of 1 × 10⁶ cm⁻². The second approach involves developing HgCdSe material using lattice matched, large area, and commercially available III–V substrates, specifically GaSb. Preliminary results indicate that quality HgCdSe growth by molecular beam epitaxy (MBE) can be achieved and that the bandgap of the material can be controlled through the Cd/Se ratio of fluxes used during growth.