Strong wavevector dependence of hole transport in heterostructures

Klimeck, Gerhard; Bowen, R. Chris; Boykin, Timothy B.

doi:10.1006/spmi.2000.0973

“…2 depicts the current densities JðkÞ as a function of transverse momentum at the different biases. At a bias of 0.15 V, JðkÞ is a smooth monotonically decreasing function, as typically expected [22,24] in RTDs. In typical RTDs such monotonic behavior is expected for all bias points.…”

Section: Off-center Current Flowmentioning

confidence: 84%

“…(2) must be performed. In fact, the limitations of the Tsu-Esaki formula have been discussed previously for direct bandgap electron systems [5,7,16,17], intra band systems [19,20] and hole transport systems [21][22][23][24]. The main effect of the breakdown of the Tsu-Esaki approximation in the structure simulated in this publication is an under-estimate of the valley current in the RTD.…”

Section: Tsu-esaki Formulamentioning

confidence: 94%

“…In typical RTDs such monotonic behavior is expected for all bias points. In fact, it has been analytically shown [22] that JðkÞ is always peaked at k ¼ 0 if the emitter and the well effective mass are the same. At higher biases of 0.3 and 0.5 V, sharp turn-ons in JðkÞ can be seen.…”

Section: Off-center Current Flowmentioning

confidence: 99%

“…The different emitter and quantum well dispersions considered here, however, distribute the sharp current peak turn-on and turn-off along a parabolic distribution. It can be shown for holes at low temperatures that the Jðk; VÞ distribution starts to represent the EðkÞ distribution [22,23]. On the linear gray scale shown in Fig.…”

Section: Off-center Current Flowmentioning

confidence: 99%

See 2 more Smart Citations

Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

Klimeck

¹

2001

phys. stat. sol. (b)

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The current turn-on and turn-off in a resonant tunneling diode (RTD) is determined by the crossing of the central resonance subband with the Fermi level in the emitter, the subbands of quasibound states in the emitter and the conduction band edge in the emitter. In a typical RTD the subbands in the central well and the emitter are similar, resulting in a simple resonant current flow for almost all transverse momenta. Since most of the electrons have zero transverse momentum, one therefore observes that most of the carriers travel straight through the structure. This paper presents a mechanism that can generate off-zone-center current flow in electron resonant tunneling diodes, where most of the carriers travel through the structure at an angle for a certain bias range. The basic idea is that if the effective mass in the RTD well is much smaller than the effective mass in the emitter, subband crossings will occur outside the zone center, resulting in this unintuitive distribution of the current as a function of transverse momentum. This mechanism is shown to increase the valley current within a single band approximation without non-parabolicity.

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“…This phenomenology, early quoted by Wessel and Altarelli in resonant tunneling [4], has been lately stressed for real-life technological devices [5]. Fundamental condensed-matter studies [6,7] had propelled us into the present modeling, since they have predicted the modification of the effective potential in the electronic case.…”

mentioning

confidence: 97%

Valence‐band effective‐potential evolution for coupled holes

Flores-Godoy

¹

,

Mendoza-Álvarez

²

,

Diago‐Cisneros

³

et al. 2013

Physica Status Solidi (b)

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We present the metamorphosis in the effective-potential profile of layered heterostructures, for several III-V semiconductor binary compounds, when the band mixing of light and heavy holes increases. A root-locus-like procedure, is directly applied to an eigenvalue quadratic problem obtained from a multichannel system of coupled modes, in the context of multiband effective mass approximation. By letting grow valence-band mixing, it is shown the standard fixed-height rectangular potential-energy for the scatterer distribution, to be a reliable test-run input for heavy holes. On the contrary, this scheme is no longer valid for light holes and a mutable effective \emph{band offset} profile has to be considered instead, whenever the in-plane kinetic energy changes.Comment: 12 pages, 5 figure

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Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

Klimeck

¹

2001

phys. stat. sol. (b)

Self Cite

0

View full text Add to dashboard Cite

The current turn-on and turn-off in a resonant tunneling diode (RTD) is determined by the crossing of the central resonance subband with the Fermi level in the emitter, the subbands of quasibound states in the emitter and the conduction band edge in the emitter. In a typical RTD the subbands in the central well and the emitter are similar, resulting in a simple resonant current flow for almost all transverse momenta. Since most of the electrons have zero transverse momentum, one therefore observes that most of the carriers travel straight through the structure. This paper presents a mechanism that can generate off-zone-center current flow in electron resonant tunneling diodes, where most of the carriers travel through the structure at an angle for a certain bias range. The basic idea is that if the effective mass in the RTD well is much smaller than the effective mass in the emitter, subband crossings will occur outside the zone center, resulting in this unintuitive distribution of the current as a function of transverse momentum. This mechanism is shown to increase the valley current within a single band approximation without non-parabolicity. 1 ) email: gekco@jpl.nasa.gov. 2 ) See http://hpc.jpl.nasa.gov/PEP/gekco/nemo, or search for NEMO on http://www.raytheon.com.

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Strong wavevector dependence of hole transport in heterostructures

Cited by 28 publications

References 42 publications

Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

Valence‐band effective‐potential evolution for coupled holes

Indirect Bandgap-Like Current Flow in Direct Bandgap Electron Resonant Tunneling Diodes

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