It is important to ascertain the functionality Cd_XHg_1-XТe arrays manufactured in MBE grown epitaxial layers under exposure to the radiation environment and try to disclose the physics of the process. The stability of CdHgТe photodiodes iv various radiation environments has been studied in [1,2]. In the present work the changes in Cd_XHg_1-XТe photodiodes’ characteristics after fast neutron radiation were studied. The photodiode arrays were formed on Cd_0,215Hg_0.785Тe film х=0.215 by implantation of B⁺ with 150 keV ion energy and dose 3´10¹³ см^-2. The film was produced on the GaAs substrate by molecular-beam epitaxy. Current-voltage characteristics were measured before and after the fast neutron radiation treatment with the dose 5´10¹³ см^-2 at the room temperature. According [1] we should expect no changes in photodiodes, because defects that caused by neutrons should be annealed at the room temperature. Quite the opposite, we observed increasing of the dark currents in the reverse bias range U<0.2 V and decreasing one in the range U>0.6 V in most photodiodes. In the other photodiodes group dark current increasing has been observed in the whole range of bias voltage. For the analysis of the changes of photodiode’s generation-recombination processes the model of the balance of the carriers on the traps in the band gap [3] was applied. The modelling shows that the dark currents increase at low bias voltage and decrease at high bias voltage only by acceptor concentration decreasing in the р – quasi neutral region and in the р–n junction. Decreasing of the acceptor –like Hg^2- vacancies concentration could be explained by the generation of vacancy-interstitial pairs of mercury under neutron radiation and diffusion of the high mobile mercury interstitials to the р–n junction with the recombination with the mercury vacancies in this region.

1. James C. Pickel, Gordon R. Hopkinson, Chery J. Marshall. Radiation Effects on Photonic Imagers – A Historical Perspective. IEEE Transaction on nuclear science, vol. 50, No. 3, June, 2003 p. 671-688.

2. F.F. Sizov, I.O. Lysiuk, J.V. Gumenjuk-Sichevska, S.G. Bunchuk, V.V. Zabudsky Gamma radiation exposure of MCT diode arrays // Semicond. Sci. Technol., 21, p. 358-363 (2006).

3. J.V. Gumenjuk-Sichevskaya, F.F. Sizov. Currents in narrow-gap photodiodes // Semicond. Sci. Technol. 14 (1999) P. 1124-1133

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/19083 must be provided.

1. Linear 288×4 long wavelength infrared mercury cadmium telluride detector
2. Matrix 320×256 infrared long wavelength detector with inner short wavelength cut-off filter
3. Properties of MBE CdxHg1-xTe/GaAs structures modified by ion-beam milling
4. MBE growth of HgCdTe layers and their properties in the context of IR applications