Differential carrier lifetime in InGaN-based light-emitting diodes obtained by small-signal frequency-domain measurements

• Published in: Journal of applied physics 2017-01, Vol.121 (3)
• Main Authors: Reklaitis, I., Nippert, F., Kudžma, R., Malinauskas, T., Karpov, S., Pietzonka, I., Lugauer, H. J., Strassburg, M., Vitta, P., Tomašiūnas, R., Hoffmann, A.
• Format: Article
• Language: English
• Subjects: Applied physics; Augers; Carrier lifetime; Continuous radiation; Frequency domain analysis; Indium gallium nitrides; Light emitting diodes; Low currents; Measurement techniques; Organic light emitting diodes; Photoluminescence; Quantum efficiency; Recombination coefficient
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4973903

Recently, a novel method for evaluation of recombination coefficients corresponding to Shockley-Read-Hall, radiative, and Auger recombination channels has been proposed, which combines measurements of the light emitting diode (LED) external quantum efficiency under continuous wave operation with the determination of non-equilibrium carrier differential life time (DLT) by small-signal time-resolved photoluminescence [Nippert et al., Jpn. J. Appl. Phys., Part 1 55, 05FJ01 (2016)]. In this work, we suggest an alternative technique, small-signal frequency-domain lifetime measurements, which is implemented more easily and capable of operating in a wider range of LED operating currents. The DLTs measured by both techniques are shown to agree well with each other, but saturate at low currents, contrary to the trend predicted by the well-known ABC-model. We discuss possible reasons for this deviation, as well as advantages and limitations of the measurement techniques.