[16p-W2_401-1~17] 15.4 III-V-group nitride crystals

3:30 PM - 3:45 PM JST(6:30 AM - 6:45 AM UTC)

[16p-W2_401-10] Significant improvement of performance in AlGaN-based UV-B laser diodes via low-temperature growth

〇Takumu Saito¹, Rintaro Miyake¹, Shundai Maruyama¹, Yusuke Sasaki¹, Shogo Karino¹, Seiya Kato¹, Naoki Kitta¹, Ryota Watanabe¹, Yuma Miyamoto¹, Shion Kamiya¹, Sho Iwayama¹, Hideto Miyake², Satoshi Kamiyama¹, Tetsuya Takeuchi¹, Motoaki Iwaya¹ (1.Meijo Univ., 2.Mie Univ.)

Keywords:

Semiconductor laser,AlGaN,UV laser diode

In MOVPE growth, the optimal temperature for high-quality nitride semiconductors strongly depends on the material, ranging from InN to AlN, and AlGaN-based UV devices have conventionally been grown at 1000–1300 °C. However, recent studies have reported that high-temperature growth degrades heterointerface abruptness due to Ga and Al interdiffusion, leading to inferior device performance. We have demonstrated that lowering the growth temperature suppresses atomic diffusion, resulting in improved MQW quality under optical excitation and enhanced carrier injection efficiency (ηi) in current-injected laser diodes. In this study, the threshold current density (Jth), internal loss (αi), and ηi are comprehensively evaluated to determine the optimal growth temperature for AlGaN-based UV-B laser diodes.