Methods for Measuring the Current-Voltage Characteristics of Photodiodes in a Multirow Infrared Photodetector

摘要

Methods for measuring the current-voltage characteristics (I-V curves) of photodiodes in a 6 x 576 mercury-cadmium-tellurium (MCT) multirow photodetector designed for operation in the longwave part of the infrared (IR) spectral range are analyzed. The I-V curve is plotted using the resultes of measurements of output signals of a large-scale readout integrated circuit (ROIC) hybridized with a row of IR photodiodes. The method of independent current measurement at each point of the I-Vcurve is compared to the method of additive current measurements. A method of determining optimum working points of photodiodes by plotting and analyzing the dependence of the differential resistance of photodiode on the bias voltage is proposed. Distributions of photodiode currents for a sample of a 6 x 576-element focal plane array (FPA) based on MCT photodiodes with a p-type conductivity substrate having the cutoff wavelength of lambda(0.5) = 10.5 mu m are considered.