基于表面钝化效应的砷化镓基太赫兹调制器性能

Performance of GaAs-based terahertz modulator based on surface passivation effect

摘要:

研究了表面化学硫硒钝化技术对砷化镓基光控太赫兹调制器件性能的增强效应和机制。实验表明，硫硒钝化能有效地去除砷化镓表面氧化物，减少表面复合中心，从而改善砷化镓的表面状态。钝化后，光致发光(PL)强度显著增强，是参考砷化镓基底的6倍。同时，钝化效应可以显著提升砷化镓中少数载流子的寿命，可达2.2 ns。表面钝化效应可以显著提高砷化镓基太赫兹调制器的调制性能，在3 mW激光功率下测得调制深度为41%，调制速率为88.81 MHz。该光控太赫兹调制器在低功率下具有高调制深度和调制速率，在太赫兹通信领域有巨大的应用潜力。

Abstract:

This paper studies the enhancement effect and mechanism of surface chemical sulfur-selenium passivation technology on the performance of gallium arsenide-based light-controlled terahertz modulation devices. Experiments show that sulfur-selenium passivation can effectively remove gallium arsenide surface oxides, reduce surface recombination centers, and improve the surface state of gallium arsenide. After passivation, the Photoluminescence(PL) intensity is significantly enhanced, which is 6 times that of the reference gallium arsenide substrate. At the same time, the passivation effect can significantly increase the lifetime of minority carriers in gallium arsenide, up to 2.2 ns. The surface passivation effect can significantly improve the modulation performance of the GaAs-based terahertz modulator. The measured modulation depth is 41% and the modulation rate is 88.81MHz under 3 mW laser power. The optically controlled terahertz modulator has high modulation depth and modulation rate at low power, and has huge application potential in the field of terahertz communication.