| || Ion Beam Based Techniques for Mercury Cadmium Telluride Infrared Detectors
Author : Pal, R;Mittal, Vandna;Sharma, R. K;Basu, P. K
Source : Defence Science Journal ; Vol:59(4) ; 2009 ; pp 395-400
Subject : 53 Applied Physics
Keywords : Infrared detectors;mercury-cadmium-telluride detectors;ion implantation;ion beam milling;detector fabrications;IR detectors;reactive ion itching;etching processes
Abstract : The paper reviews the applications of ion beam-based techniques such as ion implantation and ion beam milling, for HgCdTe detector fabrication. Fabrication of large-format arrays and two-color arrays necessitate the use of dry processes. Ion irradiation causes type conversion in HgCdTe. The type conversion is far beyond the damage sites because of Hg in-diffusion to interstitial sites. The dry processes combine high anisotropy, faster etch rates, and better dimensional control, than wet etch processes, but require the damaged region to be removed.
| || Modified Lead-zirconate-titanate for Pyroelectric Sensors
Author : Thakur, O. P.;Singh, J. P.;Prakash, Chandra;Pran Kishan
Source : Defence Science Journal ; Vol:57(3) ; 2007 ; pp 233-239
Subject : 681.586 Sensors
Keywords : PZT;IR detectors;Ceramic materials;Lead-zirconatetitanate systems;Pyroelectric sensors;Sensors
Abstract : Pyroelectric sensors based on ceramic materials have found applications in IR detection in defence and civil systems. To develop suitable ceramic material for IR detector applications, a modified PZT system with compositional formula Pb1-xSmx(Zr0.58Fe0.18Mn0.02Nb0.2Ti0.02)O3 where 0 £ x £ 0.025 was synthesised by conventional solid state reaction method. The materials were characterised for their properties like dielectric and pyroelectric coefficient. Hysteresis loop was recorded at room temperature. The sample with 2 mole per cent samarium (Sm) substitutions was found to be more promising for sensor application based on its high material's figure of merit (FOM). Sensors fabricated with this material were integrated with FET amplifier. The devices configured with compensating element were evaluated for different chopping frequencies. The value of material's FOM, FD, and detectivity, D*, were determined from measured parameters and were, 3.6 x 10-5 Pa-1/2 and 2 x 108 cmHz1/2/W, respectively.