Total sensitivity of Euclid’s photometric I_E, Y_E, J_E, and H_E, and spectroscopic BG_E, RG_E (solid and dashed lines, respectively). The sensitivity (in electrons per photon) includes all optical surfaces as well as the detectors’ average quantum efficiency, all considered at their expected EOL performance after six years at L2 (degraded by radiation damage and contamination; see e.g. Venancio et al. 2020).