[TuP3D] D. Photonic devices and related technologies

[TuP3D-09] Establishment of a Method for IQE Estimation in GaN and InGaN Using a Laser Heterodyne Photothermal Displacement Method

〇Yuta Hosokoshi¹, Atsushi Yamaguchi², Shigetaka Tomiya³, Yoshio Honda⁴, Atsuhiko Fukuyama¹ (1. Univ. of Miyazaki (Japan), 2. Kanazawa Inst. of Tech. (Japan), 3. Nara Inst. of Science and Tech. (Japan), 4. Univ. of Nagoya (Japan))

Internal quantum efficiency (IQE) is an important parameter for characterizing the quality of light-emitting devices. The IQE is usually estimated by measuring the carrier radiative transitions using a Photoluminescence (PL) method. However, quantitative IQE measurements for nitride semiconductors is usually challenging due to their large defect densities. We have now developed a Laser Heterodyne Photothermal Displacement (LH-PD) method for quantitatively estimating nonradiative transitions by measuring the surface displacement resulting from the heat generated by carrier recombinations. In this study, we calculated the ratio of carrier radiative and non-radiative recombination processes in nitride semiconductors using the LH-PD method. Establishing a method for defining the IQE of nitride semiconductors, the usefulness of our LH-PD method is proposed. Theoretical calculations assumed that all photo-excited carriers contributed to non-radiative recombination. By taking the ratio of this result to the experimental value, we can calculate the ratio of photo-excited carriers contributing to non-radiative recombination. This was calculated using Three GaN and one InGaN samples prepared in this study. In the GaN-bulk and InGaN samples, the results indicated that approximately 36.5 and 84.3% of the carriers contributed to heat generation, respectively.