Hetero-epitaxy monocrystal, hetero-junction solar cell, and manufacture methods thereof

Abstract

The invention provides a manufacture method of a hetero-epitaxy monocrystal, a manufacture method of a hetero-junction solar cell, the hetero-epitaxy monocrystal, and the hetero-junction solar cell. Accordingly, lattice defects generated in a monocrystal thin film during the time when the monocrystal thin film is grown on a monocrystal substrate can be reduced, the thin film having a lattice constant different from that of the substrate. The manufacture method of the hetero-epitaxy monocrystal is characterized in that opening parts (13) are formed on a mask layer (12) formed on the substrate (10); exposing faces (14) exposing the substrate (10) are formed on the bottom faces of the opening parts; silicon crystals (20) having a lattice constant different from that of the substrate (10) are enabled to grow on the exposing faces (14) according to the shapes of the exposing faces (14); and the width of each exposing face (14) is set to be lower than the width of the exposing face (14) at the time when the breaking strength of the silicon crystals (20) is equal to the stress generated along lattice strain subjected onto the silicon crystals (20) by the substrate (10).

Description

technical field [0001] The present invention relates to a method for manufacturing a heteroepitaxial single crystal, a method for manufacturing a heterojunction solar cell, a heteroepitaxial single crystal, and a heterojunction solar cell, in particular to a technique for reducing lattice defects in a single crystal grown on a substrate . Background technique [0002] Semiconductor materials are used as materials for solar cells, integrated circuits, and the like. Regarding solar cells, in order to further improve efficiency, there has been proposed a tandem solar cell in which another semiconductor having a different bandgap width is laminated on top of a semiconductor. In addition, with regard to integrated circuits, in order to reduce parasitic capacitance and achieve high speed, a structure in which semiconductors, which are integrated circuit materials, are laminated on an insulator has been proposed. [0003] In any of the proposals proposed above, in order to manufa...

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Problems solved by technology

[0013] However, even with the above method, there are still a large number of lattice defects such as threading dislocations in the part of the film grown on the substrate directly from the substrate, so that the entire film still has a large number of lattice defects, so the use on the substrate Devices made of thin-film heteroepitaxial growth materials are limited in terms of high performance

Of course, it is also possible to cut out and use only the laterally grown part of the above thin film, but it is difficult to form this part into a size required for devices such as solar cells and integrated circuits.

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