Fe-Cr-Si ternary amorphous thin film capable of modulating band gap width and preparation method thereof

Abstract

The invention discloses a Fe-Cr-Si ternary amorphous thin film capable of modulating band gap width and a preparation method thereof, and belongs to the technical field of semiconductor materials. The Fe-Cr-Si ternary amorphous thin film has the following general formula: Fe3Cr1Six, wherein x is 8-18; along with increase of x from 8 to 18, the band gap width increases from 0 eV to 0.65 eV; and the thin film structure is amorphous. Compared with an ordinary binary transition metal silicide thin film, the Fe-Cr-Si ternary amorphous thin film has the advantages as follows: 1, the Fe3Cr1Six thin film is a novel ternary semiconductor amorphous thin film and can modulate the band gap width within a relatively large range of 0-0.65 eV; and under the action of Cr, the band gap width can be affected and the amorphous forming capability of the thin film can be increased through addition of one element; 2, the proportion of Si in the Fe3Cr1Six thin film can be conveniently regulated only by changing the number of Fe3Cr1 alloys in a combined sputtering target, thus obtaining different band gap widths; and 3, the Fe3Cr1Six thin film is amorphous, so that the uniformity of components and the performance can be ensured, and lattice mismatch and multiphase mixing and other problems during preparation of a crystalline thin film are effectively avoided. Therefore, the Fe-Cr-Si ternary amorphous thin film is applicable to production of near infrared detectors and other semiconductor devices with narrow band gaps.

Description

technical field [0001] The invention relates to a Fe-Cr-Si ternary amorphous thin film capable of modulating the bandgap width and a preparation method thereof, belonging to the technical field of semiconductor materials. Background technique [0002] Semiconductor metal silicides are one of the materials used in solar cells. They have excellent compatibility with single crystal silicon technology, and have metal conductivity, high thermal stability, oxidation resistance and superior mechanical stability. At the same time, semiconductor Silicides have also won widespread attention due to their superior environmental friendliness, especially transition metal silicides. The typical one is β-FeSi 2 and CrSi 2 . β-FeSi 2 It has a direct band gap of 0.83~0.87eV, and has a large optical absorption coefficient for infrared wavelengths (α>10 -5 cm -1 ,1.0eV), the theoretical photoelectric conversion efficiency can reach 16~23%, which can be used to prepare high-efficiency s...

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Problems solved by technology

The crystals are also prone to defects such as stacking faults and twins, so it is difficult to obtain high-quality and pure β-FeSi 2 Material

[0005] (2) β-FeSi 2 When used in the field of optoelectronics, most of the thin films are prepared on the basis of single crystal Si, but there is a large film-base mismatch problem, resulting in many of its properties failing to meet theoretical expectations.

[0006] (3) Binary β-FeSi currently prepared using different methods 2 material, whose bandgap width varies around 0.87eV, is slightly different, but cannot be modulated

Crystalline ternary FeSi after adding the third component 2 Type materials are prone to phase separation. Although the bandgap width can be modulated in a wide range, it increases the instability of the structure and further deteriorates the situation of multiphase mixing.

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