Epitaxial Wafer of Multiple Periodic Layer for Midwavelength Infrared Detectors with High Sensitivity

摘要

Midwavelength infrared (MWIR: 3-5 μm) detectors with high sensitivity and fast response are strongly demanded for hazardous gas detection and satellite observation. In recent years, InAs/GaSb superlattices (SLs) have been a subject of intense study as the absorption region of the MWIR detector. Although organometallic vapor phase epitaxy (OMVPE) is advantageous for mass production compared with molecular beam epitaxy (MBE), the number of reports on the OMVPE growth of InAs/GaSb SLs is limited. In this work, we fabricated high-quality 100-period InAs/GaSb SLs on GaSb substrates by OMVPE. MWIR detectors with 100-period SLs showed a dark current density of 2 × 10-4 A/cm2 at -50 mV and 77 K, and an external quantum efficiency of 15% at 3.5 μm and 20 K. These results indicate that the InAs/GaSb SLs could offer excellent structural and electrical properties for high-performance MWIR detectors.