Graphene germanium-silicon quantum dot integrated composite structure detector and preparation method thereof

Abstract

The invention provides a graphene germanium-silicon quantum dot integrated composite structure detector and a preparation method thereof, the graphene germanium-silicon quantum dot integrated composite structure detector comprises a patterned Si substrate, a Si buffer layer, a plurality of GeSi quantum dot layers, a Si spacer layer, a single-layer graphene film, a SiNX passivation layer, a top electrode and a bottom electrode, the Si buffer layer is deposited on the patterned Si substrate; the single-layer graphene film, the multiple GeSi quantum dot layers and the Si spacing layer form an absorption layer; the side edge of the absorption layer and the upper surface of the patterned Si substrate are wrapped with a SiNX passivation layer; a top electrode is arranged on the single-layer graphene film; and a bottom electrode is arranged on the upper surface of the patterned Si substrate. According to the invention, the GeSi quantum dot layer with a high absorption coefficient is obtained, the absorption of incident light by GeSi quantum dots is increased, the photoelectric conversion efficiency and response of the infrared detector are improved, and the response time of the infrared detector is shortened.

Description

technical field [0001] The invention relates to the technical field of semiconductor photodetectors, in particular to a composite structure detector integrated with graphene-germanium-silicon quantum dots and a preparation method thereof. Background technique [0002] For half a century, the rapid development of optical communication and optical interconnection technology has continuously promoted people's research on photodetectors with high response and low dark current. As a traditional first-generation semiconductor material, silicon (Si) has always been a research hotspot for its photoelectric properties. Its mature microelectronic device technology makes Si devices undoubtedly have natural advantages in industrial applications. However, the inherent indirect bandgap characteristics of the Si material itself and the low first-order photoelectric coefficient lead to an extremely low photoelectric response of the Si detector, which limits its application. Improving the ph...

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Problems solved by technology

However, GeSi quantum dot infrared detectors currently reported internationally generally have key problems such as low quantum dot density, low absorption efficiency, and low absorption coefficient of quantum dots caused by uneven size distribution of epitaxially grown quantum dots.

Therefore, although GeSi quantum dot infrared detectors have some preliminary results in the laboratory, there is still a gap from practical applications. To explore ways to improve the detection efficiency of GeSi quantum dot detectors and solve the problem of low photoelectric coupling efficiency of GeSi quantum dots, for The development of Si-based integrated optoelectronic technology has important application value

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