AlInAsSb Impact Ionization Coefficients

Full band Monte Carlo simulation of AlInAsSb digital alloys

“…If the minigap in conduction band could block electrons like the case in the valence band of InAlAs digital alloy, we can infer that the ionization coefficient of electrons is lower than that of holes. However, we found in the experiment that the electron ionization coefficient is much larger than holes 8 . Apparently, minigap in the conduction band of AlInAsSb does not block the accelerating path of electrons, the electrons could find the path to jump across the minigap and gather enough energy to trigger ionizations.…”

“…Intuitively, a minigap in the conduction band would prevent electrons from achieving sufficient energy to impact ionize. However, previous work has shown that electron impact ionization occurs at a much higher rate than that of holes in the AlInAsSb digital alloy 8 . In this article, full band structure based Monte Carlo simulation is used to analyze carrier transport 9‐12 …”

“…However, previous work has shown that electron impact ionization occurs at a much higher rate than that of holes in the AlInAsSb digital alloy. 8 In this paper, full band structure based Monte Carlo simulation is used to analyze carrier transport. 9-12 FIGURE 1 A, Lattice structures for AlInAsSb digital alloy and its B, bandstructure and the two types of initial states of electrons in Monte Carlo simulation.…”

Extremely low-noise avalanche photodiodes based on AlAs0.56Sb0.44

“…Unfortunately, this small bandgap means room temperature operation of these devices is not possible and some form of cooling is required to reduce their dark currents. Recently, Campbell et al [14,15] showed that the AlInAsSb alloy had a small β/α ratio and excess noise that was comparable to, or superior to that of silicon. This material has a large bandgap of 1.24 eV and can operate at room temperature, however it has to be grown lattice matched on GaSb substrates.…”

“…Early work on AlAsSb was undertaken on extremely thin avalanching structures and while good multiplication characteristics could be obtained, the excess noise was found to increase linearly as the multiplication increased, suggesting that β/α ~ 1 and the relatively low noise seen was due to dead-space effects [16]. Ionization coefficients as a function of inverse electric field for InP [17], AlInAs [18], silicon [19] and Al0.7In0.3AsSb [15]. Both silicon and Al0.7In0.3AsSb have better k values than InP or AlInAs, especially at the lower electric fields.…”