Photovoltaic Mercury Cadmium Telluride Short Form Catalog in PDF Format

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J19TE Series Photovoltaic MCT Detectors

J19TE series detectors are high-quality HgCdTe photodiodes for use in the 500nm to 5.0um range. The equivalent circuit is a photon-generated current source Iph with parallel capacitance CD, Shunt resistance RD, and series resistance RS.

Temperature Effects: Cooling an HgCdTe photodiode reduces noise and improves detectivity. Cooling also increases shunt resistance RD HgCdTe photodiodes also improve their response at longer wavelengths with a reduction in temperature.

Figure 19	Figure 20

Figure 21	Figure 22

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Thermoelectric Cooler Operation: Figures 23, 24 and 25 show typical power requirements for the TE2, TE3, and TE4 coolers. The built in thermistor can be used to monitor or control the temperature. Figure 21 shows typical thermistor resistance vs. temperature values. Sensitivity, cutoff wavelength and response uniformity are all functions of temperature. Detector temperature should be optimized for a particular application.

Figure 23	Figure 24

Figure 25

Operating Circuit: The recommended operating circuit for most applications is an operational amplifier in a negative-feedback transimpedance configuration (Figure 22) with 0.1V reverse bias put across the detector. This reverse bias will increase the effective shunt impedance of the detector and will nullify the responsivity effect described in the J12 series operation notes.

Advantages of Photovoltaic HgCdTe: Unlike the photoconductors commonly used in the 500nm to 5.5um region, HgCdTe photodiodes operate in the photovoltaic mode and do not require a bias current for operation. This makes J19TE detectors the better choice for DC and low-frequency applications, as it does not exhibit the low frequency or "1/F" noise characteristic of the PbS, PbSe and HgCdTe photoconductors. J19TE detectors also offer superior pulse response for applications in monitoring and detecting high-speed pulsed lasers.

3CN Package

66C Package