用动态光谱响应测试技术评价多碱光电阴极的电子亲和势

Appraised Electron Affinity of Multi-alkali Photo-cathode with Dynamic Spectral Response Measure Technology

利用光谱响应和量子产额曲线首次介绍了多碱光电阴极制备过程中的电子亲和势。Na2 KSb、Na2 KSb +Cs和 [Na2 KSb +Cs]+Sb +Cs的电子亲和势分别为 0 .7～ 0 .91eV ,0 .35～ 0 .4 1eV和 0 .33eV ,并认为电子亲和势的差异取决于阴极工艺的差别。在Na2 KSb形成过程中存在n型表面态 ,这些n型表面态的存在影响了Na2 KSb的重掺杂 。

Electron affinity of multi alkali photo cathodes were introduced by spectral response curves and quantum yield in preparation firstly. The electron affinity of Na 2KSb,Na 2KSb+Cs and(Na 2KSb+Cs)+Sb+Cs is 0.70～0.91 eV,0.35～0.41 eV and 0.33 eV respective1y.The difference of the electron affinity reflects difference of photo cathode preparation technology. n type surface state induced in Na 2KSb preparation influence heavily p type doped in the Na 2KSb and sensitivity of multi alkali photo cathode.