Deep level spectroscopy of high-power laser diode arrays

Deep defect centers in high-power AlGaAs/GaAs laser diode arrays emitting at a wavelength of 808 nm are studied by Fourier-transform photocurrent spectroscopy and by electrical deep level transient spectroscopy. Different types of deep centers with binding energies between 0.15 and 0.8 eV are found in graded-index and step-index diode structures. In all structures, the defect concentration increases with operation time. We demonstrate that different operation conditions of the devices, such as regular operation or accelerated aging at increased temperatures, cause different scenarios of deep level creation. In addition to deep centers, aging leads to the formation of shallow defects and a reshaping of the absorption band edge. (C) 1998 American Institute of Physics.