公开(公告)号：WO1994001882A1

公开(公告)日：1994-01-20

申请号：PCT/GB1993001326

申请日：1993-06-24

Applicant: THIRD GENERATION TECHNOLOGY LIMITED ,  HOWORTH, Jonathan, Ross

Inventor： THIRD GENERATION TECHNOLOGY LIMITED

IPC: H01J01/35

CPC classification number: H01J43/08 ,  H01J1/34 ,  H01J2201/3423

Abstract: Photoemitters are used to convert received photons of light (or other electromagnetic radiation) into electrons, and it is common to employ an electron multiplier to amplify the low electron flux for use by an imaging or a counting system. Interest has been shown in semiconductor photoemitter and electron multiplier devices based on "mixtures" of the Group III and Group V elements gallium and arsenic or phosphorus, but these are not easy to use in a photoelectric tube. In transmissive mode these III-V materials have high sensitivity to infrared (IR), but have much poorer sensitivity to blue and ultraviolet. Now, it turns out that the III-IV materials are more blue-sensitive in reflective mode. Moreover, in this mode they are good as electron multipliers. The problem is to provide a device operating in this reflective mode with good imaging capability (the ejected electrons scatter). The present invention seeks to solve this by providing a III-V photoemitter structure where, though the photoemissive material is operating in blue-sensitive reflective mode, the device itself is operating in image-retaining transmissive mode. More specifically, the invention proposes that the III-V photoemitter layer (11) be in the form of an array of spaced III-V elements (13) the front faces of which are angled towards the gaps between the elements. Electrons (e-) ejected from the elements' front faces (by impacting photons or electrons) will, under the influence of an appropriate electrical field (E), be swept laterally towards and then through the spaces between the elements, so that though the III-V material is acting in reflective mode, and so has good blue sensitivity, the device itself is acting in transmissive mode, and so has good imaging properties. To form a photocathode/photomultiplier device a plurality of these individual III-V layers may be stacked one above the next, with the elements of each succeeding layer aligned with the gaps in the preceding layer, so that electrons ejected from each layer and passing through the gaps will impact the next adjacent layer without losing their image-defining spatial resolution.

Abstract translation: 光收发器用于将接收的光（或其他电磁辐射）的光子转换成电子，并且通常使用电子倍增器来放大由成像或计数系统使用的低电子通量。 已经在基于III族和V族元素镓和砷或磷的“混合物”的半导体光电发生器和电子倍增器装置中显示出兴趣，但这些在光电管中不容易使用。 在透射模式下，这些III-V材料对红外（IR）具有高灵敏度，但对蓝色和紫外线具有较差的灵敏度。 现在，事实证明，III-IV材料在反射模式下对蓝色敏感。 此外，在这种模式下，它们作为电子倍增器是好的。 问题在于提供一种具有良好成像能力（喷射电子散射）的这种反射模式的装置。 本发明寻求通过提供III-V光发射器结构来解决这个问题，其中尽管光发射材料以蓝色敏感反射模式操作，但是器件本身在图像保持透射模式下操作。 更具体地，本发明提出III-V光电发射体层（11）为间隔开的III-V元件阵列（13）的形式，其前表面朝向元件之间的间隙成角度。 通过适当的电场（E）的影响，从元件的正面（通过撞击光子或电子）喷出的电子（e-）将被横向扫过，然后穿过元件之间的空间，使得尽管 III-V材料以反射模式工作，因此具有良好的蓝色灵敏度，器件本身以透射模式工作，因此具有良好的成像性能。 为了形成光电阴极/光电倍增器装置，可以将多个这些单独的III-V层叠加到下一个之上，每个后续层的元素与前一层中的间隙对准，使得从每层排出的电子通过 间隙将影响下一个相邻层，而不会失去其图像定义的空间分辨率。