講演情報
[16p-K401-2]Integrated analysis of the ratio of A1(LO) and E2(high) modes energy shift in Fe-doped GaN with Raman spectroscopy
〇(D)KhaingShwe TheeEi1, Kohei Ueno2, Bei Ma1, Hiroshi Fujioka2, Yoshihiro Ishitani1 (1.Chiba Univ., 2.The Univ. of Tokyo)
キーワード：
Fe-GaN、A1(LO)、E2(high) mode energies、Raman spectroscopy
Gallium Nitride (GaN) is applied to high-power devices, light-emitting diodes (LEDs), and laser diodes. Iron (Fe) doping is important in semi-insulating devices. Many of the operational functions of electronic and photonic devices are supressed by temperature increase, where the control of phonon dynamics is indespensible. we mainly focus on the LO phonon dynamics in Fe-doped GaN. Figure 1(a) shows the ratio of the values of energy shift decrements of A1(LO) (A1LO) and E2(high) (E2H) mode by the 325-nm laser excitation. The energy decrement of A1LO mode DA1LO is over five times greater than the energy decrement of E2H mode DE2H in the case of the laser heating. Figure 1(b) shows the ratio of the value of the ratio is approximately 2 and constant in the measurement temperature range. The result indicates the anormal high mode energy decrement in the A1LO. As it is known that the electrons are firstly captured by the Fe atoms, this result indicates the A1LO is affected by the hole plasmon, which induces the mode energy decrease because of the overdamping.