University of Konstanz

Axel Herguth

Svenja Wilking

Ihor Melnyk

Barbara Terheiden

Josh Engelhardt

Giso Hahn

Gunnar Schubert

Sebastian Gloger

Daniel Sommer

Martin Käs

There are provided a method for producing a photovoltaic element with stabilised efficiency, and a device which may be used to carry out the method, for example in the form of a specially adapted continuous furnace. A silicon substrate to be provided with an emitter layer and electrical contacts is thereby subjected to a stabilisation treatment step. In that step, hydrogen, for example from a hydrogenated silicon nitride layer, is introduced into the silicon substrate, for example within a zone () of maximum temperature. The silicon substrate may then purposively be cooled rapidly in a zone () in order to avoid hydrogen effusion. The silicon substrate may then purposively be maintained, for example in a zone (), within a temperature range of from 230&#xb0; C. to 450&#xb0; C. for a period of, for example, at least 10 seconds. The previously introduced hydrogen may thereby assume an advantageous bond state. At the same time or subsequently, a regeneration may be carried out by generating excess minority charge carriers in the substrate at a temperature of at least 90&#xb0; C., preferably at least 230&#xb0; C. Overall, with the proposed method, a regeneration process in the production of a photovoltaic element may be accelerated significantly so that it may be carried out, for example, in a suitably modified continuous furnace.

Method and device for producing a photovoltaic element with stabilised efficiency

According to an example, in a method for producing a photovoltaic element with stabilised efficiency, a silicon substrate may be provided with an emitter layer and electrical contacts, which may be subjected to a stabilisation treatment step. Hydrogen from a hydrogenated silicon nitride layer may be introduced into the silicon substrate, for example, within a zone of maximum temperature. The silicon substrate may then be cooled rapidly in a zone in order to avoid hydrogen effusion. The silicon substrate may then be maintained, for example in a zone within a temperature range of from 230&#xb0; C. to 450&#xb0; C. for a period of, for example, at least 10 seconds. The previously introduced hydrogen may thereby assume an advantageous bond state. At the same time or subsequently, a regeneration may be carried out by generating excess minority charge carriers in the substrate at a temperature of at least 90&#xb0; C., preferably at least 230&#xb0; C.

What is proposed is a method of producing at least two differently heavily doped subzones () predominantly doped with a first dopant type in a silicon substrate (), in particular for a solar cell. The method comprises: The method uses the observation that a borosilicate glass layer seems to promote an in-diffusion of phosphorus from a gas atmosphere and may substantially facilitate a manufacturing for example of solar cells, in particular back contact solar cells.

Method of producing differently doped zones in a silicon substrate, in particular for a solar cell

A method for fabricating a photovoltaic element with stabilized efficiency is proposed. The method comprises the following steps: preparing a boron-doped, oxygen-containing silicon substrate; forming an emitter layer on a surface of the silicon substrate; and a stabilization treatment step. The stabilization treatment step comprises keeping the temperature of the substrate during a treatment time within a selectable temperature range having a lower temperature limit of 50&#xb0; C., preferably 90&#xb0; C., more preferably 130&#xb0; C. and even more preferably 160&#xb0; C. and an upper temperature limit of 230&#xb0; C., preferably 210&#xb0; C., more preferably 190&#xb0; C. and even more preferably 180&#xb0; C., and generating excess minority carriers in the silicon substrate during the treatment time, for example, by illuminating the substrate or by applying an external voltage. This method can be used to fabricate a photovoltaic element, e.g. a solar cell or a solar module having an efficiency which is stable at a value higher than that of photovoltaic elements fabricated without the stabilization treatment step.

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Constance, Germany

Axel Herguth