EXCIMER LASER JUNCTION ISOLATION OF CRYSTALLINE SILICON SOLAR-CELLS

Recent results have shown that an excimer laser cut trench is an effective means of providing junction isolation between the n + diffused region and the aluminum back contact of a crystalline silicon solar cell. This method was developed for processing of edge-defined film-fed growth (EFG) silicon ribbon solar cells and has several features that make it attractive for low cost solar cell processing. It is a single step, noncontacting, dry process which is conducted in air. Only 100 laser pulses are required for isolation along a 10-cm line of focus, which permits a high throughput for this process. This technique should also be applicable to other types of crystalline solar cells where cell junctions are formed by a thermal diffusion process. © 1990 IEEE