A copper-zinc-tin-sulfur-based film precursor with a cyclic quantum well structure and its preparation method

Abstract

The invention discloses a copper-zinc-tin-sulfur-based thin film precursor with a cyclic quantum well structure and a preparation method thereof. The preparation method includes: using a balance to accurately weigh the mass of the substrate before and after growth, and converting the mass by molar mass Obtain the amount of the corresponding precursor growth source material to obtain the relationship between the growth rate of the growth source, film thickness and growth time, and then control the ratio of each precursor growth source element by controlling the growth time, and then according to the growth time The division of copper-zinc-tin-sulfur-based film precursors for quantum well-like growth; also includes the use of magnetron sputtering, thermal evaporation or electron beam evaporation with high background vacuum, stable growth rate and high repeatability growth method. Based on the above preparation method, the present invention can precisely control the composition and element ratio of the thin film and its precursor, and solve the technical problem of the overall element ratio imbalance of the existing copper-zinc-tin-sulfur-based thin film.

Description

technical field [0001] The invention belongs to the technical field of semiconductor photovoltaic devices, and in particular relates to a copper-zinc-tin-sulfur-based film precursor with a cyclic quantum well structure and a preparation method thereof. Background technique [0002] The combination of renewable energy and Internet technology is the booster of the third industrial revolution. From the perspective of development trend, renewable energy such as wind energy, solar energy and biomass energy is expected to replace fossil energy in 2050; Ten years will still be an important transition period for energy development, and solar energy, as a green renewable energy, is expected to become a new force in it. After more than 10 years of hard work, my country's photovoltaic industry has become one of the strategic emerging industries with international competitiveness. [0003] At present, solar cells for large-scale industrial applications include silicon-based solar cells...

AI Technical Summary

Problems solved by technology

This gap is largely due to the difference between the copper-zinc-tin-sulfur-based thin-film material itself and the CIGS thin-film material. One of the important reasons is that the copper-zinc-tin-sulfur-based thin-film material is very sensitive to its element ratio, and its stable single The phase area is very narrow. In the actual growth process, high-temperature selenization or sulfidation is required, which can easily cause the loss of Sn and Zn elements, or the problem of local element mismatch, and the introduction of Cu 2 S(Se), ZnS(Se), SnS(Se) 2 equal quadratic phase

These secondary phases lead to different degrees of damage to the device performance of solar cells: some of them have better conductivity and narrow band gap (such as Cu 2 The secondary phase of S(Se)) is easy to form internal bulk leakage current due to its high carrier concentration, thereby reducing the working voltage of the battery; while the wide bandgap (such as ZnS(Se), SnS(Se) 2 ) secondary phase may become a recombination center inside the material; a large number of secondary phases can also easily form an insulating layer or a secondary diode, resulting in an increase in the series resistance of the material, making it difficult to export photogenerated electron-hole pairs, thereby reducing the battery output current

Images