a Light signal in least significant bits (LSB, ADC digital output) vs. impinging light intensity. Photons per frame and pixel are varied via length of the light pulse and calculated from the measured light power per cm2. The applied photodiode bias voltage was varied. The measurement was done for 2 frames per second (fps), equivalent to 500 ms integration time and 4 fps, equivalent to 250 ms integration time. A log–log plot of (a) is shown in Supplementary Fig. 5. b EQE as calculated from the slope of the graphs from (a) vs. impinging light intensity. c Temporal behavior of the image sensor. At t = 0 the light pulse is switched off, and the decay of photocurrent is monitored for different applied biases. d Optical image taken with the image sensor on foil.