Berlin 2018 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 22: Nitrides: Preparation and characterization I
HL 22.5: Vortrag
Dienstag, 13. März 2018, 15:00–15:15, EW 203
Analysis of the low temperature internal quantum efficiency of GaInN/GaN quantum wells — •Fedor Alexej Ketzer1, Torsten Langer1, Philipp Henning1, Heiko Bremers1, Uwe Rossow1, Dirk Menzel2, and Andreas Hangleiter1 — 1Institut für Angewandte Physik, TU Braunschweig — 2Institut für Physik der Kondensierten Materie, TU Braunschweig
The internal quantum efficiency (IQE), one of the key parameters for light emitting devices, is often measured by temperature dependent photoluminescence spectroscopy. By normalizing the integrated intensities at different temperatures and excitation powers to the excitation power and dividing by the maximum value one can estimate the IQE. For this estimation it is assumed that nonradiative recombination gets suppressed at low temperatures, which may be indicated by a saturation of the measured IQE. But tunneling processes with no, or a weak dependence on temperature may reduce the IQE even at low temperatures, which results in an overestimation of the IQE. Therefore we studied the absolute intensities at low temperatures as well as the IQEs for samples with changed nonradiative recombination. For this purpose we introduced intentional defects inside the quantum well region by ion implantation with different doses and compared the data with an unimplanted sample. Furthermore we investigated a set of samples with various radiative recombination rates and similar nonradiative recombination rates. From both series we estimate the IQE at low temperatures to clarify if a low temperature saturation of the temperature behavior is sufficient to neglect nonradiative recombination.