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Figure 6
Integrated signal from an optical pulsed laser source as the phase delay slides the integration window past the overlap region with the induced current pulse. Mobilities extracted from data over a range of bias voltages are used to feed the simulation model to compare with the data. (a) The response to 515 nm illumination at −250 V bias. Energy is absorbed in the top of the sensor material, so the resulting current pulse is due entirely to electrons moving through the sensor. (b) The response to 1030 nm illumination at −300 V bias. Electron/hole pairs are produced uniformly throughout the sensor depth, yielding a response curve with components from both electrons and holes. The delay as the signal initially begins to fall is a consequence of the amplifier not keeping up at higher bias voltages. The duration of the falling edge of the pulse reflects the duration of the induced photocurrent inside the CdTe sensor. |