This study presents a comprehensive optimization and comparative analysis of thermoelectric(TE)infrared(IR)detec-tors using Bi_(2)Te_(3) and Si materials.Through theoretical modeling and numerical simulations,we explo...This study presents a comprehensive optimization and comparative analysis of thermoelectric(TE)infrared(IR)detec-tors using Bi_(2)Te_(3) and Si materials.Through theoretical modeling and numerical simulations,we explored the impact of TE mate-rial properties,device structure,and operating conditions on responsivity,detectivity,noise equivalent temperature difference(NETD),and noise equivalent power(NEP).Our study offers an optimally designed IR detector with responsivity and detectivity approaching 2×10^(5) V/W and 6×10^(9) cm∙Hz^(1/2)/W,respectively.This enhancement is attributed to unique design features,includ-ing raised thermal collectors and long suspended thin thermoelectric wire sensing elements embedded in low thermal conductivity organic materials like parylene.Moreover,we demonstrate the compatibility of Bi_(2)Te_(3)-based detector fabrication pro-cesses with existing MEMS foundry processes,facilitating scalability and manufacturability.Importantly,for TE IR detectors,zT/κemerges as a critical parameter contrary to conventional TE material selection based solely on zT(where zT is the thermoelec-tric figure of merit andκis the thermal conductivity).展开更多
Some results on the molecular-beam epitaxial growth of HgCdTe focusing on the requirements of the 3rd generation infrared focal plane arrays are described. Good uniformity is observed over 75mm HgCdTe epilayers,and th...Some results on the molecular-beam epitaxial growth of HgCdTe focusing on the requirements of the 3rd generation infrared focal plane arrays are described. Good uniformity is observed over 75mm HgCdTe epilayers,and the deviation in cutoff wavelength is within 0. 1μm at 80K. A variety of surface defects are observed and the formation mechanism is discussed. The average density of surface defects in 75mm HgCdTe epiluyers is found to be less than 300cm^-2. It is found that the surface sticking coefficient of As during HgCdTe growth is very low and is sensitive to growth temperature, being only -1 × 10^-4 at 170℃. The activation energy of As in HgCdTe was determined to be 19.5meV,which decreases as （Na - Nd）^1/3 with a slope of 3.1 × 10^-5 meV · cm. The diffusion coefficients of As in HgCdTe of 1.0 ± 0,9 × 10^-16,8 ± 3 × 10^- is, and 1.5 ± 0.9 × 10^-13 cm^2/s are obtained at temperatures of 240,380, and 440℃, respectively under Hg-saturated pressure. The MBE-grown HgCdTe is incorporated into FPA fabrications,and the preliminary results are presented.展开更多
基金supported by the National Science Foundation (NSF)under grant number CBET-2110603.
文摘This study presents a comprehensive optimization and comparative analysis of thermoelectric(TE)infrared(IR)detec-tors using Bi_(2)Te_(3) and Si materials.Through theoretical modeling and numerical simulations,we explored the impact of TE mate-rial properties,device structure,and operating conditions on responsivity,detectivity,noise equivalent temperature difference(NETD),and noise equivalent power(NEP).Our study offers an optimally designed IR detector with responsivity and detectivity approaching 2×10^(5) V/W and 6×10^(9) cm∙Hz^(1/2)/W,respectively.This enhancement is attributed to unique design features,includ-ing raised thermal collectors and long suspended thin thermoelectric wire sensing elements embedded in low thermal conductivity organic materials like parylene.Moreover,we demonstrate the compatibility of Bi_(2)Te_(3)-based detector fabrication pro-cesses with existing MEMS foundry processes,facilitating scalability and manufacturability.Importantly,for TE IR detectors,zT/κemerges as a critical parameter contrary to conventional TE material selection based solely on zT(where zT is the thermoelec-tric figure of merit andκis the thermal conductivity).
文摘Some results on the molecular-beam epitaxial growth of HgCdTe focusing on the requirements of the 3rd generation infrared focal plane arrays are described. Good uniformity is observed over 75mm HgCdTe epilayers,and the deviation in cutoff wavelength is within 0. 1μm at 80K. A variety of surface defects are observed and the formation mechanism is discussed. The average density of surface defects in 75mm HgCdTe epiluyers is found to be less than 300cm^-2. It is found that the surface sticking coefficient of As during HgCdTe growth is very low and is sensitive to growth temperature, being only -1 × 10^-4 at 170℃. The activation energy of As in HgCdTe was determined to be 19.5meV,which decreases as （Na - Nd）^1/3 with a slope of 3.1 × 10^-5 meV · cm. The diffusion coefficients of As in HgCdTe of 1.0 ± 0,9 × 10^-16,8 ± 3 × 10^- is, and 1.5 ± 0.9 × 10^-13 cm^2/s are obtained at temperatures of 240,380, and 440℃, respectively under Hg-saturated pressure. The MBE-grown HgCdTe is incorporated into FPA fabrications,and the preliminary results are presented.
