This paper describes the history and current status of HgCdTe infrared detector technology at BAE Systems in
Lexington, Massachusetts, whose corporate legacy includes Honeywell (1962-1991), Loral (1991-1996), and Lockheed
The Honeywell Radiation Center was founded in 1962 in Boston, Massachusetts. Shortly thereafter, primitive
HgCdTe samples began to arrive from the Honeywell Corporate Research Center in Hopkins, Minnesota for evaluation
as possible IR detectors. In 1967, procedures for the growth of HgCdTe inhomogeneous large-grain-polycrystalline
ingots by a modified Bridgman method were transferred from the Research Center to the Radiation Center. In 1968 the
Radiation Center moved to new facilities in Lexington, Massachusetts. HgCdTe activities have expanded and evolved in
the ensuing years, remaining in the Lexington, Massachusetts facilities up to the present.
This paper reviews the role that the Honeywell/Loral/Lockheed Martin/BAE Systems facility in Lexington,
Massachusetts has played in the success of HgCdTe as today's preeminent, highest performance, most versatile, and
most widely applicable infrared detector material for the 1-30 μm spectral range.
We examine the evolution of both photoconductive and photovoltaic HgCdTe detectors from early unpassivated
ill-understood single-element devices through production of linear arrays and to today's large-format two-dimensional
IR Focal Plane Arrays for the most demanding spaceborne applications. We examine the progress made in HgCdTe
materials science and technology, including improved highly-homogeneous bulk crystal growth, liquid phase epitaxy
and metalorganic vapor phase epitaxy. Various devices are used to illustrate the evolution of HgCdTe technology,
including the n-type photoconductor, the trapping-mode photoconductor, and the two-layer LPE P-on-n heterojunction.