Hybrid pixel detectors (HPDs) have been shown to be highly effective for diffraction-based and time-resolved studies in transmission electron microscopy, but their performance is limited by the fact that high-energy electrons scatter over long distances in their thick Si sensors. An advantage of HPDs compared to monolithic active pixel sensors is that their sensors do not need to be fabricated from Si. We have compared the performance of the Medipix3 HPD with a Si sensor and a GaAs:Cr sensor using primary electrons in the energy range of 60–300 keV. We describe the measurement and calculation of the detectors’ modulation transfer function (MTF) and detective quantum efficiency (DQE), which show that the performance of the GaAs:Cr device is markedly superior to that of the Si device for high-energy electrons.

混合像素检测器（HPD）已被证明对于透射电子显微镜中基于衍射和时间分辨的研究非常有效，但是其性能受到高能电子在厚硅传感器中长距离散射的事实的限制。与单块有源像素传感器相比，HPD的优势在于它们的传感器不需要由Si制成。我们比较了使用60-300 keV能量范围内的一次电子的Si传感器和GaAs：Cr传感器的Medipix3 HPD的性能。我们描述了检测器的调制传递函数（MTF）和探测量子效率（DQE）的测量和计算，结果表明，对于高能电子，GaAs：Cr器件的性能明显优于Si器件。