Comparison of optimal performance at 300 keV of three direct electron detectors for use in low dose electron microscopy

TL;DR

This study compares the performance of three direct electron detectors at 300 keV for low dose electron microscopy, focusing on their modulation transfer function and detective quantum efficiency to optimize imaging quality.

Contribution

The paper provides a detailed comparison of three commercially available direct electron detectors, highlighting their relative performance in terms of DQE and MTF at 300 keV.

Findings

All three detectors outperform film in DQE.

K2 Summit has the highest DQE at low spatial frequencies.

Falcon II surpasses K2 Summit at higher spatial frequencies.

Abstract

Low dose electron imaging applications such as electron cyro-microscopy are now benefitting from the improved performance and flexibility of recently introduced electron imaging detectors in which electrons are directly incident on backthinned CMOS sensors. There are currently three commercially available detectors of this type: the Direct Electron DE 20, the FEI Falcon II and the Gatan K2 Summit. These have different characteristics and so it is important to compare their imaging properties carefully with a view to optimising how each is used. Results at 300 keV for both the modulation transfer function (MTF) and detective quantum efficiency (DQE) are presented. Of these, the DQE is the most important in the study of radiation sensitive samples where detector performance is crucial. We find that all three detectors have a better DQE than film. The K2 Summit has the best DQE at low spatial frequencies but with increasing spatial frequency its DQE falls below that of the Falcon II.