Solar cells testing using different diagnostic method

conference paper

English

The LBIC (light beam induced current) method is generally used for detection of local defects in solar cells. But this method is too slow. The LBIC analysis is widely used as a universal method for detecting local defects in the solar cell structure. Scanning of the solar cell surface with a single point light source (laser or LED focused beam) could take several hours of processing time depending on the required picture resolution. A method for fast scanning of solar cells based on the LBIC measurement was proposed and tested. Instead of the laser beam a linear light source consisting of multiple SMD LED diodes is used. Scanning is performed in both X and Y axes. In principle, one scan in each coordinate is sufficient. The improvement of technique was done in the field of an enhanced light strip. Several types of line light sources were tested and their properties were compared. The width of the line light beam is adapted to the pinstripe with the help of a cylindrical lens. A high resolution of measurement is warranted by the exact and fast reading of measured data. Another way of defect detection is the electroluminescence imaging (EL). In EL imaging a forward bias is applied to the finished solar cells. A higher contrast between the white and the black area is attained in consequence of uneven distribution of current density. All process steps can be scanned by a CCD camera. In this work it is possible to compare LBIC method with electroluminescence - preferences and deficiencies, mutual comparison.

solar cells, testing, electroluminescence

JANDOVÁ, K.; JANDA, M.; VANĚK, J.; BAŘINKA, R.

2008

27. 3. 2008

Nakladatelství ČVUT

Praha

978-80-01-04047-8

4th IWTPV'08

1

69

72

4