D X-center-like traps and persistent photoconductivity in Te-doped AlxGa1−xSb on GaSb

Publisher Website
Google Scholar
Abstract
The donor‐related deep electron traps in Te‐doped Alx Ga1−x Sb on GaSb substrate were investigated by deep level transient spectroscopy, capacitance‐voltage, photocapacitance, and Hall‐effect measurements. Deep electron traps were not detected in the Al composition range 0≤xx. The concentration of the deep electron traps increases steeply with x and then saturates. The concentration also increases linearly with donor concentration for the same Al composition. In the temperature‐dependent Hall‐effect measurement, both shallow donor and deep donor levels were observed. The deep donor is dominant for x≥0.4, and the thermal activation energy E0 increases dramatically from 6 to 110 meV in the range of 0.2<x≤0.5. Persistent photoconductivity was observed for x≥0.3 at temperatures below 100 K. All the experimental results indicate that the deep electron traps in Te‐doped Alx Ga1−x Sb are quite similar to the DX center in Alx Ga1−x As.