An electron detector assembly configured for detecting electrons emitted from a sample irradiated by an electron beam, including a scintillator configured with a scintillator layer formed with a scintillating surface. The scintillator layer emits light signals corresponding to impingement of electrons upon the scintillating surface. A light guide plate is coupled to the scintillator layer and includes a peripheral surface. One or more silicon photomultiplier devices are positioned upon the peripheral surface, wherein one or more silicon photomultiplier devices are arranged perpendicularly or obliquely relative to the scintillating surface. The silicon photomultiplier device is configured to yield an electrical signal from an electron impinging upon the scintillator surface.