[20a-E202-1~10] 15.4 III-V-group nitride crystals

[20a-E202-3] Influence of Self Absorption in Two-Photon-Excitation Photoluminescence of GaN

〇Tomoyuki Tanikawa¹, Kazunobu Kojima², Shigefusa Chichibu², Takashi Matsuoka¹ (1.IMR, Tohoku Univ., 2.IMRAM, Tohoku Univ.)

Keywords:GaN, Two-Photon-Excitation Photoluminescence, Urbach Tail

Influence of self-absorption in the two-photon-excitation phtoluminescence (2PPL) of GaN was investigated. The intensity at the higher energy side of GaN's near-band-edge emission dropped drastically with deepening the excitation position. This is due to the self-absorption, which occurs when the emission light escapes from the GaN crystal. The change of 2PPL intensity occurred in the energy range higher than 3.3 eV, which is lower than the absorption edge of GaN. Thus the 2PPL spectral shape is influenced by the self-absorption of so-called Urbach tails.