Crystalline Silicon Device Loss Analysis Through Spatially Resolved Quantum Efficiency Measurements

The development of ultrafast quantum efficiency measurements has made it possible to perform spatially resolved short-circuit current mapping on large area crystalline silicon solar cells. With the inclusion of concurrent diffuse reflectance measurements, detailed loss analysis is presented that identifies the impact and spatial nonuniformity of various current loss mechanisms. We measure p-type multicrystalline aluminum back surface field and p-type monocrystalline passivated emitter and rear cells, and investigate details of the spatial variation in specific device layers such as the antireflection coating, phosphorus diffused region, bulk, and rear surface. The results are compared with traditional photoluminescence imaging, and are found to provide a complementary dataset that provides a comprehensive picture of device performance. The insight provided from these techniques is intended to allow rapid feedback for quality control in manufacturing and accelerate the pace of process development in research environment.