The performance of HgCdTe barrier detectors with cut-off wavelengths up to 3.6 μm fabricated using metaloorganic chemi- cal vapour deposition operated at high temperatures is presented. The detectors’ architecture consists of four layers: cap contact, wide bandgap barrier, absorber and bottom contact layer. The structures were fabricated both with n- and p-type absorbing layers. In the paper, different design of cap-barrier structural unit (n-B_p′, n⁺-B_p′, p+-B_p) were analysed in terms of various electrical and optical properties of the detectors, such as dark current, current responsivity time constant and detectivity.

The devices with a p-type cap contact exhibit very low dark current densities in the range of (2÷3)×10^-4 A/cm² at 230 K and the maximum photoresponse of about 2 A/W in wide range of reverse bias voltage. The time constant of measured de- vices with n-type cap contact and p-type absorbing drops below 1 ns with reverse bias while the detectivity is at the level of 1010 cm ^∙ Hz1/2/W.