STU-GTIIT光学论坛（No.30）
报告地点：at lecture hall E310 in the north campus of GTIIT
报告时间：2024年11月19日 17:00
报告题目: Next generation wide bandgap semiconductors: Insights into nonlinear dynamics （全英）
报告人：Ahsan Ali（Guangdong Technion Israel Institute of Technology, Shantou 515063, China）
报告摘要:
Wide-bandgap (WBG) semiconductors have become important in photonic technologies due to their large optical bandgap, low losses, and high-speed operation. Emerging materials like gallium nitride (GaN) and silicon carbide (SiC) are positioned to surpass traditional silicon-based devices, offering unique advantages such as broad transparency windows, high refractive indices, nonlinearities, superior thermal conductivity, high electron saturation velocity, and robust breakdown electric fields. To fully leverage these materials, a detailed understanding of nonlinear phenomena such as harmonic generation, phase modulation, wave mixing, and multiphoton absorption (MPA) is essential for defining their device functionalities. We have quantified the multiphoton photocurrent in GaN and SiC photodetectors using a highly sensitive technique based on phase-modulated femtosecond pulses. Results reveal that GaN undergoes single, two, and three-photon absorption (1PA, 2PA, and 3PA), while SiC only exhibits four-photon absorption (4PA) under ultrashort high-intensity pulses. These findings open new avenues for understanding ultrafast intrinsic processes in WBG semiconductors, highlighting their potential in next-generation photonic applications.
Ali, A., Wang, C., Cai, J. and Karki, K.J., 2024. Probing silicon carbide with phase-modulated femtosecond laser pulses: Insights into multiphoton photocurrent. ACS Photonics, 11(4), pp.1502-1507.
Wang, C., Ali, A. and Karki, K.J., 2024. Multiphoton photocurrent in wide bandgap semiconductors for nonlinear optoelectronics: Comparison of GaP, GaN/InGaN, and SiC. Applied Physics Letters, 124(6).
Wang, C., Cai, J., Liu, X., Chen, C., Chen, X. and Karki, K.J., 2023. In operando quantification of single and multiphoton photocurrents in GaP and InGaN photodetectors with phase-modulated femtosecond light pulses. ACS Photonics, 10(4), pp.1119-1125.
欢迎全校师生参加！
理学院
2024年11月19日
