Indirect bandgap-like current flow in direct bandgap electron resonant tunneling diodes

Authors
Citation
G. Klimeck, Indirect bandgap-like current flow in direct bandgap electron resonant tunneling diodes, PHYS ST S-B, 226(1), 2001, pp. 9-19
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICA STATUS SOLIDI B-BASIC RESEARCH
ISSN journal
0370-1972 → ACNP
Volume
226
Issue
1
Year of publication
2001
Pages
9 - 19
Database
ISI
SICI code
0370-1972(200107)226:1<9:IBCFID>2.0.ZU;2-L
Abstract
The current turn-on and turn-off in a resonant tunneling diode (RTD) is det ermined by the crossing of the central resonance subband with the Fermi lev el in the emitter, the subbands of quasi bound states in the emitter and th e 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 c urrent now for almost all transverse momenta. Since most of the electrons h ave zero transverse momentum, one therefore observes that most of the carri ers travel straight through the structure. This paper presents a mechanism that can generate off-zone-center current now in electron resonant tunnelin g diodes, where most of the carriers travel through the structure at an ang le for a certain bias range. The basic idea is that if the effective mass i n the RTD well is much smaller than the effective mass in the emitter, subb and crossings will occur outside the zone center, resulting in this unintui tive distribution of the current as a function of transverse momentum. This mechanism is shown to increase the valley current within a single band app roximation without non-parabolicity.