Method for inspecting a photovoltaic element, and photovoltaic element which is inspected using such a method
A method for inspecting a photovoltaic element includes providing a photovoltaic element and providing a dark characteristic curve of the photovoltaic element at a specific voltage applied to the photovoltaic element. Individual segments dividing the photovoltaic element without separation are defined. The method includes measuring characteristic curves of the individual segments of the photovoltaic element in a time sequence and illuminating the individual segments with an illumination device at the specific voltage applied to the photovoltaic element. Further, the method includes moving the photovoltaic element along a running direction relative to the illumination device and/or moving the illumination device along a running direction relative to the photovoltaic element; and ascertaining an overall characteristic curve of the photovoltaic element as a function of the dark characteristic curve and the measured characteristic curves of the individual segments, so that the photovoltaic element is able to be inspected.
1 . A method for inspecting a photovoltaic element, comprising:
providing a photovoltaic element;
providing a dark characteristic curve of the photovoltaic element at a specific voltage applied to the photovoltaic element,
wherein the dark characteristic curve is a characteristic curve measured when the photovoltaic element is completely darkened;
defining individual segments of the photovoltaic element, the individual segments dividing the photovoltaic element without separation;
measuring characteristic curves of the individual segments of the photovoltaic element in a time sequence;
illuminating the individual segments with an illumination device at the specific voltage applied to the photovoltaic element;
moving the individual segments of the photovoltaic element along a running direction relative to the illumination device and/or moving the illumination device along a running direction relative to the individual segments of the photovoltaic element; and
ascertaining an overall characteristic curve of the photovoltaic element as a function of the dark characteristic curve and the measured characteristic curves of the individual segments, such that the photovoltaic element is able to be inspected,
wherein ascertaining the overall characteristic curve of the photovoltaic element comprises summing photocurrents ascertained from the dark characteristic curve of the photovoltaic element and photocurrents ascertained from the measured characteristic curves of the individual segments.
2 . The method as claimed in claim 1 , wherein the individual segments are illuminated over their entire photoactive area.
3 . The method as claimed in claim 1 , wherein the individual segments of the photovoltaic element are each illuminated at least homogeneously.
4 . The method as claimed in claim 1 , wherein a segment of the photovoltaic element has no overlap and no gap with a previous segment and/or with a following segment in the running direction.
5 . The method as claimed in claim 1 , wherein a photoactive area of the photovoltaic element is completely covered by the individual segments.
6 . The method as claimed in claim 1 , further comprising providing the dark characteristic curve before or after the measuring the characteristic curves; and wherein the dividing the photovoltaic element into individual segments and the measuring of the characteristic curves occur simultaneously or concurrently.
7 . The method as claimed in claim 1 , wherein the dark characteristic curve of the photovoltaic element is a dark characteristic curve in complete or largely complete darkness.
8 . The method as claimed in claim 1 , further comprising measuring at least one further curve at the specific voltage applied to the photovoltaic element and in ambient light when ambient light is present.
9 . The method as claimed in claim 8 , wherein the individual segments and/or the photovoltaic element are not illuminated by the illumination device, and wherein the ascertaining the overall characteristic curve comprises ascertaining the overall characteristic curve as a function of the at least one further characteristic curve in ambient light.
10 . The method as claimed in claim 8 , wherein the ascertaining the overall characteristic curve comprises subtracting photocurrents of ambient light ascertained from the further measured characteristic curves of the individual segments in ambient light.
11 . The method as claimed in claim 1 , wherein a length of the segments in the running direction is 10 cm to 10 m.
12 . The method as claimed in claim 1 , further comprising dividing the photovoltaic element into individual segments depending on an area illuminated by way of the illumination device.
13 . The method as claimed in claim 1 , wherein the method is performed in a roll-to-roll process, and/or wherein the photovoltaic element is a flexible photovoltaic element.
14 . A photovoltaic element inspected using a method as claimed in claim 1 .