Light detector of semiconductor quantum well

Abstract

The invention belongs to the technical field of light wave detectors, and particularly relates to a light detector of a semiconductor quantum well. The detector comprises a semiconductor layer, a quantum layer and a layer of a subwavelength periodic structured metal film. The quantum well at least comprises two energy levels and has a certain carrier concentration. Incident light wave with a certain spectrum width enters the semiconductor layer vertically or obliquely; the incident light wave stimulates the periodic structured metal film/a surface plasma of a quantum well interface; the surface plasma is absorbed by the semiconductor quantum well and an electronic subband transition process is generated; and the transited electrons form current signals under the externally applied bias voltage. According to the light detector of the semiconductor quantum well disclosed by the invention, the detection efficiency can be greatly improved.

Description

technical field [0001] The invention belongs to the technical field of light wave detectors, in particular to a semiconductor quantum well photodetection device. Background technique [0002] The use of quantum well structure devices for light detection is one of the main technologies for light detection in the mid- and far-infrared bands. However, on the one hand, the light wave absorption of the semiconductor quantum well structure is limited by the "polarization selection law" widely recognized in this field, that is, the quantum well can only absorb the light wave of the electric field component perpendicular to the quantum well plane, and in practical applications For direct vertically incident light wave absorption is extremely small, see Document 1 for example. Therefore, the actual device must be combined with complex processes such as oblique incidence (such as document 2), grating coupling (such as document 3) or etched groove structure (such as document 4). Thes...

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Problems solved by technology

[0003] In the disclosed technology of using a periodic metal hole structure as an optical coupling device for a quantum well photodetector, the main application is a layer of metal hole array structure, and the incident light is incident from one side of the metal layer. Although this coupling device is relatively The efficiency of oblique incidence and grating coupling in the early stage has been improved to some extent, but the efficiency is still low (absorption rate 7-10%, such as literature 7); at the same time, it is impossible to realize the combination of multiple surface plasmon modes and characteristic frequencies in semiconductors. coupling

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