Growth of fully doped Hg1−xCdxTe heterostructures using a novel iodine doping source to achieve improved device performance at elevated temperatures

摘要: Band gap engineered Hg1−xCdxTe (MCT) heterostructures should lead to detectors with improved electro-optic and radiometric performance at elevated operating temperatures. Growth of such structures was accomplished using metalorganic vapor phase epitaxy (MOVPE). Acceptor doping arsenic (As), phenylarsine (PhAsH2), demonstrated 100% activation reproducible control over a wide range concentrations (1 × 1015 3.5 1017 cm−3). Although from elemental iodine showed the suitability as donor in MC.T, problems arose while controlling low concentrations. Initial studies ethyliodide (EtI) that this source could be used successfully dope MCT, yielding properties required for stable heterostructure devices, i.e. ≈100% activation, no memory diffusion coefficient. Cryogenic alkyl cooling or very high dilution factors were achieve needed below ≈1016cm−3 due pressure alkyl. A study an alternative organic iodide source, 2-methylpropyliodide (2 MePrI), which has much lower pressure, 2 MePrI same EtI ≈ 1 5 1017cm−3. The both sources only incorporated during CdTe cycles interdiffused multilayer process (IMP) similar manner As PhAsH2. High resolution secondary ion mass spectroscopy analysis IMP scale modulations can still identified after growth. magnitude these oscillations is consistent coefficient of≈7 10−16cm2s−1 MC.T 365°C. Extrinsically doped device heterostructures, grown MePrI, have been intended operate temperatures either long wavelength (8–12 smm) equilibrium operation 145K nonequilibrium 190 295K 3–5 µ 8–12 ranges. Characterization will discussed. Linear arrays mesa devices fabricated layers. Medium wave quantum efficiencies R0A = 37 Ωcm2 λco 4.9 190K.