Theoretical analysis and experimental study of optical loss of metal contacts of crystalline silicon solar cells

One main factor of restricting industrial crystalline solar cell efficiency is the optical losses caused by the metal front side contacts, including the absorption loss and reflection loss. Based on screen-printed and screen-printed seed layers thickened by light-induced electroplating solar cells, in this paper various cases of optical losses due to the metal contacts are analyzed. Taking into account the reflections in the air-glass interface and the edge regions of metal contacts, the optical losses are simulated by assuming approximately half-oval cross-section of metal contacts. The results show that the effective width ratio is about 40% of the metal contact geometry width. By measuring and calculating the reflection spectra of different types of samples, the optical losses of the metal front side contacts of solar cells are obtained in theoretical simulation and experimental measurement. The corresponding theory and the experimental results are in good agreement with each other.