Portal de Periódicos da CAPES

InAs/GaSb superlattice focal plane arrays for high-resolution thermal imaging

2006; Elsevier BV; Volume: 14; Issue: 1 Linguagem: Inglês

10.2478/s11772-006-0003-3

1896-3757

Robert Rehm, M. Walther, J. Schmitz, J. Fleißner, F. Fuchs, Johann Ziegler, Wolfgang A. Cabanski,

Chalcogenide Semiconductor Thin Films

Abstract The first fully operational mid-IR (3–5 μm) 256×256 IR-FPA camera system based on a type-II InAs/GaSb short-period superlattice showing an excellent noise equivalent temperature difference below 10 mK and a very uniform performance has been realized. We report on the development and fabrication of the detecor chip, i.e., epitaxy, processing technology and electro-optical characterization of fully integrated InAs/GaSb superlattice focal plane arrays. While the superlattice design employed for the first demonstrator camera yielded a quantum efficiency around 30%, a superlattice structure grown with a thicker active layer and an optimized V/III BEP ratio during growth of the InAs layers exhibits a significant increase in quantum efficiency. Quantitative responsivity measurements reveal a quantum efficiency of about 60% for InAs/GaSb superlattice focal plane arrays after implementing this design improvement.