Emitter effects in shallow bipolar devices: Measurements and consequences

Wieder, A.W.

doi:10.1109/t-ed.1980.20048

Cited by 78 publications

(5 citation statements)

References 5 publications

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“…We obtained intrinsic radiative lifetimes of the order of 10 –4 s, almost 3 orders of magnitude shorter than those of bulk cubic Si . These relaxation times are shorter than the experimentally measured Auger lifetimes in bulk cubic Si − for a majority carrier density of 10 17 cm –3 , thus in the low carrier concentration limit, radiative decay is predicted to be the dominant recombination mechanism. Increasing the Ge concentration should further shorten these values, as the bandgap narrows and the conduction band minimum acquires a stronger Ge character.…”

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confidence: 65%

Optical Emission in Hexagonal SiGe Nanowires

Cartoixà

Palummo

Hauge³

et al. 2017

Nano Lett.

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Recent advances in the synthetic growth of nanowires have given access to crystal phases that in bulk are only observed under extreme pressure conditions. Here, we use first-principles methods based on density functional theory and many-body perturbation theory to show that a suitable mixing of hexagonal Si and hexagonal Ge yields a direct bandgap with an optically permitted transition. Comparison of the calculated radiative lifetimes with typical values of nonradiative recombination mechanisms indicates that optical emission will be the dominant recombination mechanism. These findings pave the way to the development of silicon-based optoelectronic devices, thus far hindered by the poor light emission efficiency of cubic Si.

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confidence: 65%

Optical Emission in Hexagonal SiGe Nanowires

Cartoixà

Palummo

Hauge³

et al. 2017

Nano Lett.

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“…So far, solar cells have been mostly simulated with empirical BGN models that were derived from electronic measurements 25,[32][33][34][35][36][37][38][39][40][41][42][43] of highly doped silicon, as is shown in Fig. 3.…”

Section: B Apparent Versus Theoretically Derived Band-gap Narrowingmentioning

confidence: 99%

Numerical modeling of highly doped Si:P emitters based on Fermi–Dirac statistics and self-consistent material parameters

Altermatt

Schumacher

Cuevas

et al. 2002

Journal of Applied Physics

165

100

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We have established a simulation model for phosphorus-doped silicon emitters using Fermi-Dirac statistics. Our model is based on a set of independently measured material parameters and on quantum mechanical calculations. In contrast to commonly applied models, which use Boltzmann statistics and apparent band-gap narrowing data, we use Fermi-Dirac statistics and theoretically derived band shifts, and therefore we account for the degeneracy effects on a physically sounder basis. This leads to unprecedented consistency and precision even at very high dopant densities. We also derive the hole surface recombination velocity parameter S po by applying our model to a broad range of measurements of the emitter saturation current density. Despite small differences in oxide quality among various laboratories, S po generally increases for all of them in a very similar manner at high surface doping densities N surf. Pyramidal texturing generally increases S po by a factor of five. The frequently used forming gas anneal lowers S po mainly in low-doped emitters, while an aluminum anneal ͑Al deposit followed by a heat cycle͒ lowers S po at all N surf .

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“…(4.2) are set as follows. The coefficient a e in n-doped Si at 300 K is measured to be 1.6 × 10 −31 cm 6 s −1 [40]. It is expected to follow a temperature dependence of T 0.72 [35].…”

Section: Auger Recombination Coefficientmentioning

confidence: 93%

Sources of Low-Energy Events in Low-Threshold Dark-Matter and Neutrino Detectors

Egaña-Ugrinovic

Essig

et al. 2022

Phys. Rev. X

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The reach of sub-GeV dark-matter detectors is at present severely affected by low-energy events from various origins. We present the theoretical methods to compute the single-and few-electron events that arise from secondary radiation emitted by highenergy particles as they pass through detector materials and perform a detailed simulation to quantify them at (Skipper) CCD-based experiments, focusing on the SENSEI data collected at Fermilab near the MINOS cavern. The simulations account for the generation of secondaries from Cherenkov and luminescent recombination radiation; photo-absorption in the bulk, backside layer, pitch adapter, and epoxy; the photon reflection and refraction at interfaces; thin-film interference; the roughness of the interfaces; the dynamics of charges produced in the highly doped CCD-backside-layers; and the partial charge collection on the CCD backside. We consider several systematic uncertainties, notably those stemming from the backside modeling, which we estimate with a "fiducial" and an "extreme" charge-diffusion model, with the former model being preferred due to better agreement with partial-charge collection data. We find that Cherenkov photons constitute about 40% of the observed single-electron events for both diffusion models; radiative recombination contributes negligibly to the event rate for the fiducial model, although it can dominate over Cherenkov for the extreme model. We also estimate the fraction of 2-electron events that arise from 1-electron event coincidences in the same pixel, finding that the entire 2-electron rate can be explained by coincidences of radiative events and spurious charge. Accounting for both radiative and non-radiative backgrounds, we project the sensitivity of future Skipper-CCD-based experiments to different dark-matter models. For light-mediator models with dark-matter masses of 1, 5, and 10 MeV, we find that future experiments with 10-kg-year exposures and successful background mitigation could have a sensitivity that is larger by 9, 3, and 2 orders of magnitude, respectively, when compared to an experiment without background improvements.

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Emitter effects in shallow bipolar devices: Measurements and consequences

Cited by 78 publications

References 5 publications

Optical Emission in Hexagonal SiGe Nanowires

Optical Emission in Hexagonal SiGe Nanowires

Numerical modeling of highly doped Si:P emitters based on Fermi–Dirac statistics and self-consistent material parameters

Sources of Low-Energy Events in Low-Threshold Dark-Matter and Neutrino Detectors

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