High gain-adaptive readout of the light-sensitive quantum dots photodetectors array

We discuss the readout of a kind of novel 64-pixel quantum dots photodetector array which has high current gains but low dark currents and thus has high signal to noise ratio. Photocurrent spectrum tests demonstrated that the photodetector shows excellent light absorption from 600nm to 900nm both in room temperature (300K) and liquid nitrogen temperature. High gain-adaptive capacitive trans-impedance amplifier (CTIA) readout circuit has been designed to acquire photocurrents. Different integration capacitors were designed to suit for both weak and nature light. In weak light detection, there were 2mV voltage response in 10^-13W @300K and 4mV in 10^-14W @77K at 2pF integration capacitor. Their responsivities were 2×10¹⁰V/W and 4×10¹¹V/W respectively.