SBIR-STTR Award

nBn Technologies will research the ability to make a new III-V compound alloy using InAsBi for long wave IR applications. The objective of the proposed research is to find a procedure for growing materials using Bismuth and characterize them by morphology, photoluminescence, x-ray diffraction, hall, etc. For applications needing cutoff wavelengths of 5 um, 10um, 12 um and even up to 20um, a different and new material is needed, especially for use in the nBn concept [1]. It will be very desirable to grow the absorbent n material for nBn structures as an alloy that lattice matches the substrate for defect reduction, easier manufacturing, and higher yields. This alloy of course can be used in pn junction structures, too. It is desired to use the III-V material system, rather than II-VI. The absorber alloy needs to be made from InAsX material if we would like to use nBn devices. In such cases, we can use the barrier (already used for MWIR nBn) for blocking majority carriers, transferring minority carriers, and at the same time used as passivation.

Keywords:
Nbn, Inasbi, Longwave, Mbe, Compound Alloy

In this program nBn Technologies proposes to developed new nBn FPAs for long wave IR. This is based on III-V material systems grown in MBE. We will concentrate on material systems that will fit the nBn concept, especially holes transport and passivation free (the barrier used as passivation).The progress for this new material system has been very significant. We have successfully demonstrated that the new system InAs-InAsSb, GaSb free, is more than suitable to be the new material for long-wave nBn detectors.The core effort of the Phase II program will be to further develop and fabricate four prototype nBn FPAs and 2 cameras that demonstrate Long Wave nBn. In addition data for single element of two colors MWIR-LWIR nBn detector will presented, through utilization of Ga free InAsSb material. Current Long Wave cooled infrared FPAs for military application are mainly base on HgCdTe, QWIPs or GaSb/InAs SLS-II. All three technologies have disadvantages that result in poor solutions for the MDA.HgCdTe ? Small FPAs very low operability very expensive material system. QWIPS: low QE, high dark current. InAa/GaSb SLS-II: low QE (need ~10um material growth for 50% QE, low operability (mesa type devices require passivation, large arrays are very limited).

Keywords:
Nbn, Focal Plane Arrays, Longwave Ir, Two Color Mw/Lw, Ga Free, Iii-V Material Systems