No abstract

The bulk generation-recombination processes and the carrier lifetime in mid-wave infrared and long-wave infrared liquid nitrogen cooled HgCdTe alloys Direct and phonon-assisted (PA) indirect Auger and radiative recombination lifetime in HgCdTe, InAsSb, and InGaAs is calculated and compared under different lattice temperatures and doping concentrations. Using the Green's function theory, the electron self energy computed from the electron-phonon interaction is incorporated into the quantum-mechanical expressions of Auger and radiative recombination, which renders the corresponding minority carrier lifetime in the materials due to both direct and PA indirect processes. Specifically, the results of two pairs of materials, namely, InAs 0.91 Sb 0.09 , Hg 0.67 Cd 0.33 Te and In 0.53 Ga 0.47 As, Hg 0.38 Cd 0.62 Te with cutoff wavelengths of 4 lm and 1.7 lm at 200 K and 300 K, respectively, are presented. It is shown that for InAs 0.91 Sb 0.09 and Hg 0.67 Cd 0.33 Te, when the lattice temperature falls below 250 K the radiative process becomes the limiting factor of carrier lifetime in both materials at an n-type doping of 10 15 cm À3 , while at a constant temperature of 200 K, a high n-type doping (N D > 5 Â 10 15 cm À3 for InAs 0.91 Sb 0.09 and 3 Â 10 15 cm À3 for Hg 0.67 Cd 0.33 Te) makes the Auger process dominate. For the Auger lifetime in In 0.53 Ga 0.47 As and Hg 0.38 Cd 0.62 Te, the calculation suggested that under all the temperatures and n-doping concentrations investigated in this paper, radiative process is always the limiting factor of the materials' minority carrier lifetime. The calculation of the PA indirect Auger process in the four materials further demonstrated its indispensable contribution to the materials' total Auger rate especially at low temperature, which is necessary to reproduce some experimental data. By fitting the Beattie-Landsberg-Blakemore (BLB) formula to the numerical Auger results, the corresponding overlap integral factors jF 1 F 2 j in BLB theory are evaluated and presented to facilitate fast and accurate Auger calculations in the IR detector simulations. V C 2015 AIP Publishing LLC. [http://dx.

The potential applications of germanium and its alloys in infrared silicon-based photonics have led to a renewed interest in their optical properties. In this letter, we report on the numerical determination of Auger coefficients at T = 300 K for relaxed and biaxially strained germanium. We use a Green's function based model that takes into account all relevant direct and phonon-assisted processes and perform calculations up to a strain level corresponding to the transition from indirect to direct energy gap. We have considered excess carrier concentrations ranging from 1016 cm−3 to 5 × 1019 cm−3. For use in device level simulations, we also provide fitting formulas for the calculated electron and hole Auger coefficients as functions of carrier density.

The Ge_1-xSn_x alloy is a promising material for optoelectronic applications. It offers a tunable wavelength in the infrared (IR) spectrum and high compatibility with complementary metal-oxide-semiconductor (CMOS) technology. However, difficulties in growing device quality Ge_1-xSn_x films has left the potentiality of this material unexplored. Recent advances in technological processes have renewed the interest toward this material paving the way to potential applications. In this work, we perform a numerical investigation on absorption coefficient, radiative recombination rate, and Auger recombination properties of intrinsic and doped Ge_1-xSn_x for application in the extended-short wavelength infrared and medium wavelength infrared spectrum ranges. We apply a Green's function based model to the Ge_1-xSn_x full electronic band structure determined through an empirical pseudopotential method and determine the dominant recombination mechanism between radiative and Auger processes over a wide range of injection levels.

Emission spectra of avalanching n + p junctions manufactured in a standard CMOS technology with no process modifications were measured over a broad photon energy spectrum ranging from 0.8 eV to 2.8 eV at various temperatures. The temperature coefficients of the emission rates at different photon energies were determined. Below a photon energy of 1.35 eV the temperature coefficient of emission was positive, and above 1.35 eV the temperature coefficient was negative. Two narrowband emissions were also identified from the temperature characterization, namely an enhanced positive temperature coefficient at 1.15 eV photon energy, and an enhanced negative temperature coefficient at 2.0 eV. Device simulations and Monte Carlo simulations were used to interpret the results. 5848-5856 (1992). 13. K. Xu and G. P. Li, "A novel way to improve the quantum efficiency of silicon light-emitting diode in a standard silicon complementary metal-oxide-semiconductor technology," J. Appl. Phys. 113, 103106 (2013). 14. S. Tam, F-C. Hsu, C. Hu, R. S. Muller and P. K. Ko, "Hot-electron currents in very short channel MOSFET's," IEEE Electron Device Lett. 4(7), 249-251 (1983). 15. J. Yuan and D. Haneman, "Visible electroluminescence from native SiO2 on n-type Si substrates," J. Appl.Phys. 86(4), 2358-2360 (1999). 16. L. Heikkilä, T. Kuusela and H.-P. Hedman, "Electroluminescence in Si/SiO2 layer structures," J. Appl. Phys. 89(4), 2179-2184 (2001). 17. A. M. Emel'yanov, N. A. Sobolev, T. M. Mel'nikova and S. Pizzini, "Efficient silicon light-emitting diode with temperature-stable spectral characteristics," Semiconductors 37(6), 730-735 (2003).