[16p-Z27-1~15] 15.4 III-V-group nitride crystals

[16p-Z27-8] Discrete AlN Mole Fraction Observed in AlGaN Layer with Dense Macrosteps (3)

〇Yosuke Nagasawa¹, Kazunobu Kojima², Akira Hirano¹, Hideki Sako³, Ai Hashimoto³, Ryuichi Sugie³, Masamichi Ippommatsu¹, Yoshio Honda⁴, Hiroshi Amano⁴, Isamu Akasaki⁵, Shigefusa Chichibu² (1.UV Craftory Co. Ltd., 2.Tohoku Univ. IMRAM, 3.Toray Research Center Inc., 4.Nagoya Univ. IMaSS, 5.Meijo Univ.)

Keywords:AlGaN, DUV, LED

Electroluminescence (EL) spectra emitted from dies in wafers fabricated with our standard UVB and UVC LED recipes respectively have featured shoulder peak wavelengths at (283, 287, 292, and 297 nm) and (257, 262, 266, and 271 nm). The samples have Al_bGa_1-bN quantum wells (QWs) with target b values of ~0.35 and 0.45 on n-Al_aGa_1-aN (a~0.6 and 0.7), respectively, grown on a 1° miscut c(0001) sapphire with respect to m[1-100] axis. EL wavelengths of the AlGaN QWs were calculated to show that the peaks can be assigned to the emission from Al_1/3Ga_2/3N and Al_1/2Ga_1/2N with the thicknesses of n monolayer (ML) (n=7–10 and 5–7). The results suggest Al mole fractions in the QWs are likely to have specific values of n/12 (n=4 and 6) with 1-ML-structures stuck in the c[0001] direction.