中文摘要：

研究了高温Cs激活过程中,GaAs光电阴极表面势垒的变化机理。在考虑GaAs材料体内负电性p型掺杂杂质与材料表面正电性Cs＋所形成的偶极子对表面势垒的作用后,通过求解均匀掺杂阴极中电子所遵循的一维连续性方程,得到了反射式均匀掺杂阴极的量子效率公式,通过求解薛定谔方程得到了到达阴极表面的光电子的逸出概率公式,利用公式对GaAs光电阴极的Cs激活过程进行了分析。分析发现,激活过程中GaAs光电阴极的量子效率和光电子的逸出概率正比于偶极子层的电场强度。

英文摘要：

Mechanism about the change of GaAs phtotocathode’s surface barrier during Cs activated process was studied.Ionized Cs and p type doping impurity（Be） form a dipole that decreases the vacuum level of GaAs.Generally,Cs activated GaAs photocathode could achieve zero electron affinity state.The quantum yield formula of reflection-mode photocathode has been solved from the 1-diemnsion continuity equations and the escape probability formula has been solved from the Schrodinger equation.It was found from the formula that the quantum efficiency of Cs activated GaAs photocathode is directly proportional to the electric field intensity of Be--Cs＋ dipole.A Cs activation experiment was carried out,the experiment process tallies with the theory mentioned above and the integral sensitivity of Cs activated GaAs photocathode is 453 μA·lm-1,which could be inferred as a zero electron affinity state.