Optoelectronics is the science and technology of electronic materials and devices that produce, detect, and control light electronically. The broad societal impact of this field is well illustrated by the ubiquitous camera-phone. Much of our modern military is also enabled by optoelectronic devices, which provide capabilities such as night-vision, 24-hour surveillance, seeing through obscurants, and threat detection, to name a few. Optoelectronic research in the ESTD is focused on advancing the capabilities of infrared sensor technologies with new materials and approaches.
Image taken with an infrared camera utilizing the NRL-produced infrared focal plane.
Image taken with an infrared camera utilizing the NRL-produced infrared focal plane.

ESTD optoelectronic research is focused on the IR spectrum, the portion of the electromagnetic spectrum just beyond the visible, ranging from approximately 1-30 μm. ESTD researchers are advancing IR materials, sensors, and detectors by controlling the interaction of light with electronic materials. A Major thrust of this work is the design and synthesis of new materials with specific bandstructure parameters, since by controlling the electronic band structure, one can control the response of the material to incident light.

This research starts with quantum mechanical modeling, using in-house developed tools, to simulate and appraise new material designs and their novel optoelectronic properties. Promising designs are brought to reality by employing atomically precise growth techniques such as molecular beam epitaxy (MBE) and chemical synthesis, followed by device fabrication in NRL's Institute for Nanoscience clean room. The resulting materials and devices are evaluated thoroughly by ESTD's staff of experienced scientists equipped with state-of-the-art characterization facilities. The experimental results provide feedback for refinements in design and growth, ultimately leading to demonstrations of new sensor capabilities, and paths for transitioning those capabilities to the warfighter.

In this manner, ESTD researchers have played a key role in the development of the most important infrared material systems for military applications over the last three decades including HgCdTe, InDb, type-II superlattices, and InAsSb alloys.

Manipulating the size and shape of colloidal nanostructures such as PbSe nanocrystals, nanorods, and nanowires, ESTD scientists are also producing IR-sensitive films that can be used for flexible sensors and detectors. The future of the IR research lies in further manipulation of materials at the atomic level to enable precise control of the optoelectronic response.