NEA GaN光电阴极的响应特性研究
时间:2017-05-06 11:08 来源:毕业论文 作者:毕业论文 点击:次
| 摘要本文简要介绍了 NEA GaN光电阴极的激活设备以及激活评估的完整步骤。讨论了Cs/O 激活后在 GaN表面所形成的双偶极层，以此为基础计算电子逸出几率。再通过逸出几率公式研究表面势垒（I、II势垒）对电子逸出几率的影响。 根据Spicer的三步发射机理，从微观的角度描写了NEAGaN光电发射的详细理论过程。 在光谱响应测试实验结果分析的基础上推导了透射式和反射式 NEA GaN光电阴极的量子效率公式。通过公式讨论了不同工作模式下，影响阴极量子效率的因素包括电子逸出几率 P、电子扩散长度 LD、后界面复合速率Sv、阴极发射层的厚度Te、 、阴极材料对入射光的吸收系数、阴极材料对入射光的反射率 R。8203 关键词GaN光电阴极 激活评估 逸出几率 光电发射 光谱响应 量子效率 Title Research of NEA GaN photocathode response characteristic Abstract Activation device and steps of activation and evaluation of the NEA GaN photoelectric cathode is introduced In this thesis. The dipole layer formed on the surface of GaN after the activation with Cs/O is discussed, as the basis for calculating the escape probability of electron. Through the formula of escape probability effects of surface barrier( I, II barrier )had on electron escape probability are analyzed. According to three emission mechanism of Spicer, at the aspect of microscopic the detailed process of NEA GaN photoelectric emission theory is described. Quantum efficiency formula of the transmissive and reflective NEA GaN photocathode is deduced based on analysis of the results of the spectral response test experimental. Factors influencing the cathode quantum efficiency under different working modes is discussed through the formula, including Electron escape probability P, electron diffusion length LD, interface composite rate Sv, cathode emission layer thickness, Te, cathode materials on the incident light absorption coefficientα, cathode materials on the reflectance of incident light R. Keywords GaN photoelectric cathode activation and assess escape probability photoelectric emission spectral response quantum efficiency 目次 1 绪论 1 1.1 NEA GaN光电阴极概述 . 1 1.1.1 NEA GaN 阴极光电发射基本原理 1 1.1.2 NEA GaN 阴极结构与工作模式 2 1.2 GaN光电阴极研究现状 . 3 1.3 NEA GaN 光电阴极的应用 . 4 1.3.1 NEA GaN 光电阴极在微弱紫外探测领域的应用 . 4 1.3.2 NEA GaN 光电阴极在真空电子源中应用 5 1.4 本文研究背景和意义 . 6 1.4.1本文研究背景 . 6 1.4.2本文研究依据及意义 . 7 1.5本文研究的主要工作 7 2 NEA GaN光电阴极的光电发射机理 8 2.1概述 8 2.2 NEA GaN光电阴极光电发射过程 . 11 2.2.1光电子激发 11 2.2.2光电子往阴极表面的输运 12 2.2.3光电子隧穿表面势垒 13 3．NEA GaN激活工艺及光电阴极表面势垒对电子逸出几率影响 14 (责任编辑：qin) |