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研究了变掺杂浓度结构对GaAs负电子亲和势光电阴极积分光电灵敏度的影响.通过MBE生长了两组GaAs同质外延样品.其中一组采用了均匀掺杂的单层结构,Be掺杂浓度为1×1019cm-3;另一组采用了变掺杂的多层结构,从衬底开始Be的掺杂浓度依次为1×1019,7×1018,4×1018和1×1018cm-3.负电子亲和势光电阴极通过在高真空系统中交替通入Cs和O激活得到.在线光谱响应测试曲线表明,多层Be掺杂结构光阴极的积分光电灵敏度比单层Be掺杂结构光阴极的积分光电灵敏度至少提高了50%.两种结构的GaAs样品表现出不同的表面应力情况.
The effect of varying doping concentration on the photodecomposition sensitivity of GaAs negative-electrode potential photocathode was investigated. Two sets of GaAs homoepitaxial samples were grown by MBE. One of the samples had a uniformly doped monolayer structure and Be doped The concentration of 1 × 10 19 cm -3; the other group using a variable doped multilayer structure, starting from the substrate Be doping concentrations were 1 × 1019, 7 × 1018, 4 × 1018 and 1 × 1018cm-3. Negative electron affinitive photocathodes were obtained by alternately activating Cs and O in a high vacuum system.The in-line spectral response curves showed that the integrated photodetector of the multi-layer Be-doped photocathode was more sensitive than the monolayer Be-doped photocathode Of the integral optical sensitivity increased by at least 50% .Two kinds of structure of GaAs samples show different surface stress conditions.