Modulation doped radiation emitting semiconductor device
AssigneeRegents of the University of Minnesota
InventorMichael Shur
Life of this patent
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Abstract
A radiation-emitting semiconductor device (i.e. an LED or laser) emits radiation produced by radiative recombination of electrons from a field induced two-dimensional (2-d) electron gas with holes from a field induced two-dimensional (2-d) hole gas. The device uses a narrower band semiconductor active layer sandwiched between two layers of a wider band semiconductor. Top and bottom gates are used to induce the electron and hole 2-d gasses in the active layer. N+ and P+ regions are used to contact the 2-d electron and hole gasses to provide separate biasing. The thickness of the active layer is such that a field induced PN junction or PIN structure is formed at which radiative recombination can occur.
Claims13
A radiation emitting semiconductor device for emitting radiation based upon recombination of electrons and holes comprising:
- a layered structure including:
- a first gate electrode for applying a first electric field;
- a second gate electrode for applying a second electric field;
- a narrow band gap semiconductor layer between the first and second gate electrodes within which radiative recombination takes place between electrons from a first field-induced channel and holes from a second field-induced channel;
- a first wide band gap semiconductor layer sandwiched between the first gate electrode and the narrow band gap semiconductor layer, the first wide band gap semiconductor layer having a wider band gap than the narrow band gap semiconductor layer, wherein the first wide band gap semiconductor layer and the narrow band gap semiconductor layer form a first heterojunction for confining electrons, so that upon application of the first electric field by the first gate electrode the first field-induced channel for electrons is formed in the narrow band gap semiconductor layer adjacent to the first heterojunction;
- and
- a second wide band gap semiconductor layer sandwiched between the narrow band gap semiconductor layer and the second gate electrode, the second wide band gap semiconductor layer having a wider band gap than the narrow band gap semiconductor layer, wherein the second wide band gap semiconductor layer and the narrow band gap semiconductor layer form a second heterojunction for confining holes, so that upon application of the second electric field by the second gate electrode the second field-induced channel for holes is formed in the narrow band gap semiconductor layer adjacent to the second heterojunction;
- an n+ region contacting the layered structure for providing electrical contact to the first field-induced channel in the narrow band gap semiconductor layer;
- a p+ region contacting the layered structure for providing electrical contact to the second field-induced channel in the narrow band gap semiconductor layer;
- a first electrical contact contacting the n+ region;
- and
- a second electrical contact contacting the p+ region.
Dependencies are inferred from the claim text.