A device for controlled bending of solar cells

V pričujočem diplomskem delu je opisan razvoj naprave za kontrolirano ukrivljanje sončnih celic. S tem, ko celico ukrivimo se v njej pojavijo mehanske napetosti, ki povzročijo povratne in nepovratne spremembe, kot npr. pokanje materiala in kontaktnih plasti. Te lahko zaznamo z raznimi diagnostičnimi tehnikami, kot so elektro- in fotoluminiscenca. Naprava omogoča ponovljive poskuse izvajanja mehanskih obremenitev sončnih celic z znanim polmerom in silo vse do zloma sončne celice, medtem ko izvajamo meritve. Naprava je sestavljena iz dvižnega dela in vpetja sončne celice. Dvižni del vsebuje dvižno vodilo z dajalnikom pozicije in merilno celico za merjenje sile. Dvižno vodilo dviguje orodje, ki deluje neposredno na sončno celico. Z napravo nadzorovano ukrivimo sončno celico in pri tem opazujemo odzive celice glede na določen odmik ali silo. Preliminarni test naprave na polikristalni sončni celici kvadratne oblike dimenzije 156 mm x156 mm je uspel. Meritve so pokazale, da omenjena celica zdrži mehanske obremenitve do 6 N ali pomike do 45 mm, pri čemer, elektroluminiscenčni posnetki kažejo postopno formiranje razpok.This thesis discusses the development of a device suited for controlled bending of solar cells. When the solar cells bend, mechanical stress appears in it, causing reversible and irreversible changes, such as cracking of the material or contact layers. These changes can be detected by various diagnostic techniques such as electro- and photoluminescence. The presented device performes repeatable loading of a solar cell up to a predefined radius and force all the way to the breakage of the solar cell while performing measurements. The device consists of a lifting part and a solar cell mount. The lifting part contains a lifting guide with a position encoder and a measuring cell for measuring the force. The lifting guide lifts the tool, which acts directly on the solar cell. The device bends the solar cell in a controlled manner, observing the cell\u27s responses to a certain distance or force. A preliminary test of the device on a square-shaped polycrystalline solar cell with the dimension of 156 mm x 156 mm was successful. The measurements showed that the solar cell can withstand mechanical loads of up to 6 N or displacements of up to 45 mm, with electroluminescent images showing the gradual formation of cracks