A manufacturing method includes steps of forming a texture on a surface of a single-crystalline silicon substrate, cleaning the surface of the single-crystalline silicon substrate using ozone, depositing an intrinsic silicon-based layer on the texture on the single-crystalline silicon substrate, and depositing a conductive silicon-based layer on the intrinsic silicon-based layer, in this order. The single-crystalline silicon substrate before deposition of the intrinsic silicon-based layer has a texture size of less than 5 m. A recess portion of the texture has a curvature radius of less than 5 nm. After deposition of at least a part of the intrinsic silicon-based layer and before deposition of the conductive silicon-based layer, the intrinsic silicon-based layer is subjected to a plasma treatment in an atmosphere of a gas mainly composed of hydrogen.

This photovoltaic device is provided with a crystalline semiconductor substrate, and a first amorphous layer formed on the main surface of the substrate. At the interface between the substrate and the first amorphous layer, electrical conductivity can be improved while suppressing an increase in recombination centers, and power generation efficiency can be improved by having a p-type dopant density profile that decreases stepwise in the film thickness direction from the vicinity of the interface with the substrate.

A solar cell manufacturing method includes: forming a first amorphous semiconductor layer of one conductivity type on a main surface of a semiconductor substrate; forming an insulation layer on the first amorphous semiconductor layer; etching to remove the insulation layer and the first amorphous semiconductor layer in a predetermined first region; forming a second amorphous semiconductor layer of an other conductivity type on the insulation layer after the etching, the other conductivity type being different from the one conductivity type; and etching to remove the second amorphous semiconductor layer in a predetermined second region, wherein the etching to remove the insulation layer and the first amorphous semiconductor layer in a predetermined first region includes: applying an etching paste to the insulation layer in the predetermined first region; and etching to remove the insulation layer and the first amorphous semiconductor layer in the predetermined first region using the etching paste.

Photodetector structures and methods of manufacture are provided. The method includes forming undercuts about detector material formed on a substrate. The method further includes encapsulating the detector to form airgaps from the undercuts. The method further includes annealing the detector material causing expansion of the detector material into the airgaps.

Disclosed is a manufacturing method of a solar cell, including forming a photoelectric converter including an amorphous semiconductor layer, forming an electrode connected to the photoelectric converter, and performing a post-treatment by providing light to the photoelectric converter and the electrode.

A photovoltaic structure can include two or more sets of parallel conductive fingers on a top surface and a bottom surface, such that the fingers can collect an electric current from the underlying photovoltaic structure. A scribing system can scribe a groove of a predetermined depth near and perpendicular to the plurality of fingers of the photovoltaic structure, and the photovoltaic structure can be cleaved along the groove to produce multiple strips that each can include a set of parallel fingers. An adhesive dispense system may deposit a band of conductive adhesive that can overlap a set of parallel fingers on each strip, and the strips may be overlapped over the conductive adhesive to form a string of cascaded strips. An adhesive-curing system can include an oven that may cure the conductive adhesive on one or more strips of the string at a time.

There is provided a photoelectric conversion element which includes an n-type single crystal silicon substrate (1). The n-type single crystal silicon substrate (1) includes a central region (11) and an end-portion region (12). The central region (11) is a region which has the same central point as the central point of the n-type single crystal silicon substrate (1) and is surrounded by a circle. The diameter of the circle is set to be a length which is 40% of a length of the shortest side among four sides of the n-type single crystal silicon substrate (1). The central region (11) has a thickness t1. The end-portion region (12) is a region of being within 5 mm from an edge of the n-type single crystal silicon substrate (1). The end-portion region (12) is disposed on an outside of the central region (11) in an in-plane direction of the n-type single crystal silicon substrate (1), and has a thickness t2 which is thinner than the thickness t1. The end-portion region (12) has average surface roughness which is smaller than average surface roughness of the central region (11).

A solar cell of the present invention includes a collecting electrode on one main surface of a photoelectric conversion section. The collecting electrode includes first and second electroconductive layers in this order from the photoelectric conversion section side, and an insulating layer between the first and second electroconductive layers, the insulating layer having an opening section formed therein. The first electroconductive layer is covered with the insulating layer, contains a low-melting-point material, and is conductively connected with a part of the second electroconductive layer via the opening section. The surface roughness of the second electroconductive layer is preferably 1.0 m to 10.0 m. The second electroconductive layer is preferably formed by a plating method. In order to conductively connect the first and second electroconductive layers, annealing of the first electroconductive layer by heating is preferably performed prior to forming the second electroconductive layer.

Methods for fabricating busbar and finger metallization over TCO are disclosed. Rather than using expensive and relatively resistive silver paste, a high conductivity and relatively low cost copper is used. Methods for enabling the use of copper as busbar and fingers over a TCO are disclosed, providing good adhesion while preventing migration of the copper into the TCO. Also, provisions are made for easy soldering contacts to the copper busbars.

Disclosed are embodiments of a thin-film photovoltaic technology including a single-junction crystalline silicon solar cell with a photonic-plasmonic back-reflector structure for lightweight, flexible energy conversion applications. The back-reflector enables high absorption for long-wavelength and near-infrared photons via diffraction and light-concentration, implemented by periodic texturing of the bottom-contact layer by nanoimprint lithography. The thin-film crystalline silicon solar cell is implemented in a heterojunction design with amorphous silicon, where plasma enhanced chemical vapor deposition (PECVD) is used for all device layers, including a low-temperature crystalline silicon deposition step. Excimer laser crystallization is used to integrate crystalline and amorphous silicon within a monolithic process, where a thin layer of amorphous silicon is converted to a crystalline silicon seed layer prior to deposition of a crystalline silicon absorber layer via PECVD. The crystalline nature of the absorber layer and the back-reflector enable efficiencies higher than what is achievable in other thin-film silicon devices.