Low-frequency noise versus deep level transient spectroscopy of InAs/GaSb superlattice mid-wavelength infrared detectors

Deep level transient spectroscopy (DLTS) is widely spread characterization method of traps in semiconductor material, however, it is hardly applicable to devices with a high leakage current. Due to this reason, DLTS results for narrow-band semiconductor devices are still lacking. In many cases, low-frequency noise spectroscopy (LFNS) can overcome the limitations of DLTS, because current fluctuations instead of the transient capacitance are analyzed. In the paper, the duality and complementarity of deep level transient spectroscopy and low-frequency noise spectroscopy is demonstrated and discussed for InAs/GaSb superlattice mid-wavelength IR detector with unipolar bulk barrier. The trap activation energy E
_A
= 300 meV is obtained with both techniques; however, LFNS detects a few other trap activation energies, namely E
_A
= 240 meV, 180 meV, and 130 meV, while the DLTS found also E
_A
= 490 meV.