Nanostructures for dislocation blocking in infrared detectors: Dislocation Reduction In Infrared Detector Materials Grown on Si Substrates Using Nan

The Phase I objective is to demonstrate dislocation reduction in both cadmium telluride (CdTe) and subsequent HgCdTe epitaxial layers grown on silicon substrate using an intermediate nanocrystalline CdTe buffer layer of optimized thickness and size. Nanocrystalline CdTe buffer layer will be deposited on silicon substrate by low cost processing method/s. The method consists of (a) Colloidal synthesis of CdTe nanocrystals, (b) Nanocrystalline film deposition by spin coating and (c) Chemical treatment of the film to remove the ligands and passivate the surface. MOCVD will be used first to nucleate, selectively, a thin CdTe template film on nanocrystalline CdTe buffer. Both MOCVD and MBE techniques will then be used to deposit epitaxial CdTe and HgCdTe layers to determine which technique is most suitable for achieving dislocation density reduction. Growth by MOCVD and MBE will be carried out at Rensselaer Polytechnic Institute (RPI) and Army Research Laboratory (ARL), respectively. Phase II, HgCdTe-IR material device structure with reduced dislocation density will be grown. LWIR-HgCdTe detector will be fabricated and tested. Samples of CdTe epitaxial layers with low dislocation density will be provided to ARO, ARL and Night Vision laboratories for evaluation at their facilities.