Silicon-based molybdenum disulfide heterojunction photoelectric sensor and preparation method

Abstract

The invention belongs to the field of photoelectric sensors, and provides a silicon-based molybdenum disulfide heterojunction photoelectric sensor and a preparation method thereof, so as to overcome the shortcoming of a complex preparation process of the existing multi-layer molybdenum disulfide / silicon heterojunction photodetector. The multi-layer molybdenum disulfide is directly disposed on theupper surface of a silicon substrate without precise transfer, a photoresist is directly used as an insulating layer, the use of a SiO2 layer is effectively avoided, a top electrode is directly disposed right above the multi-layer molybdenum disulfide through a window opened in the photoresist, the top electrode preparation difficulty is greatly reduced, the structure is simple, and the preparation process difficulty is small. Besides, the sensor expresses good photoelectric response in visible light and near-infrared regions, the response time can reach 150 to 200 [mu]s, and the sensitivity is thus higher.

Description

technical field [0001] The invention belongs to the field of photoelectric sensors, and relates to the preparation of a two-dimensional material heterojunction photoelectric sensor, in particular to a silicon-based molybdenum disulfide heterojunction photoelectric sensor and a preparation method thereof. Background technique [0002] With the rapid development of science and technology and the continuous progress of society, people have more and more demands for information; the integration technology of optoelectronic devices involves various fields such as military and national economy. Information systems play an increasingly important role in the evolution and development process. The band gap of transition metal sulfides changes with the number of layers, which makes them very suitable for applications in optoelectronic devices; among various transition metal sulfides, molybdenum disulfide (MoS 2 ) has been extensively studied as the most representative material. [0...

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Problems solved by technology

However, MoS 2 The light absorption efficiency is determined by the number of layers, and the single-layer MoS 2 The light absorption rate is also low, resulting in a low photoresponse current; with the increase of the number of layers, the band gap further decreases while the light absorption rate increases, so the multilayer molybdenum disulfide with more than 10 layers has a lower High photoresponse current and can detect near-infrared light

[0004] Da Ye Song et al. have reported a multilayer molybdenum disulfide / silicon heterojunction photodetector and its fabrication method. The device structure is as follows: figure 2 As shown; the preparation process of this structure is extremely complicated, and it is first necessary to etch SiO 2 layer as an insulating layer; secondly, it is required to accurately transfer small-sized molybdenum disulfide to Si and SiO 2 The edge of this operation is extremely difficult to control; at the same time, the electric field applied by the electrodes to the heterojunction region is a transverse electric field, which makes it difficult to achieve the effect of rapid separation of photogenerated carriers, making it difficult to improve the response time

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