The aim of the thesis is to suggest a comprehensive and inexpensive method of diagnosing the solar cell quality via a conventional digital camera. The following questions are answered, Can a conventionaldigital camera be used for diagnosing the quality of solar cells?; If so,is the experimental setup for the quality diagnosing constrained to a laboratory and single solar cells or can it be done in a private home for a full-sized solar panel?; What are the defects that can be observed in this experiment? A conventional digital camera has been modified to acquire the electroluminescence (EL) images and dark thermography(RevEL) images. The experiment has been done in two locations with different types of samples. Multi-crystalline p-type single solar cells are used during the laboratory experiment. In the experiment set up at the private home, a conventional solar panel with 36 quadraturemulti crystalline silicon solar cells, that are equivalent to 9 full solarcells, is used. The EL imaging has been performed under the forward bias whereas the dark thermography imaging has been performed under reverse bias. The contrast in EL images is due to the radiativeand non-radiative recombination of injected excess minority charge carriers. A large non-radiative recombination site produces a large dark area in the EL image. Similarly, the contrast in RevEL images is due to the generation of charge carriers that are associated with the non-radiative recombination sites in the depletion layer. A large defect area produces a large bright area in the RevEL image. Hence,the EL image and the RevEL image are some what inverted images of each other. It is also found that the IV characteristics and the semi-log curves are in a good agreement with the EL and the RevEL images. When the EL image is combined with the hand-on devices like a mobile camera and a macro lens, it reveals defected areas like finger-interruptions, microcracks, grain boundaries and planar defects. Whereas the RevEL images, when combined with the image processing software tool, reveal the morphology of the defected sites. This justifies the beauty and the simplicity of using an every day digitalcamera as a diagnostic tool for the quality control of the solar cell
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kau-84493 |
| Date | January 2021 |
| Creators | Lama, Arjun |
| Publisher | Karlstads universitet, Institutionen för ingenjörsvetenskap och fysik (from 2013) |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf, application/pdf |
| Rights | info:eu-repo/semantics/openAccess, info:eu-repo/semantics/openAccess |
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