LBIC Measurements on Busbarless Crystalline Silicon Solar Cells

Abstract: The importance of further research in the field of solar cells is crucial for the transition to cleaner energy. The aim of this project is to design and manufacture a contact system that can measure busbarless solar cells with an LBIC-system. In this project mono-crystalline busbarless solar cells were utilized, busbarless solar cells only have small fingers that go vertically. When an incident photon hits the solar cell it can be absorbed by the bulk material, by the pn-junction an electrical field will set the electrons in motion so an electrical current can be harvested. LBIC, which stands for light beam induced current is a technique to spatially map the quantum efficiency of a solar cell, there is also an availability to make phasemeasurements. There are two different quantum efficiencies, External quantum efficiency (EQE) and Internal quantum efficiency (IQE). The phase measurement of the LBIC shows how much resistance exists between the point of current-generation and the contacts where the current is collected. A contact system with a comb-like figure of phosphor bronze was manufactured and mounted on to the LBIC-machine. Several measurements were executed on two solar cells. This new contact system can measure busbarless solar cells, with a good connection to almost all the fingers on the solar cell. The lack of contact with some fingers seemed to not affect the end result too much. It isn’t vital to have contact with all fingers to get a decent LBIC-mapping.