Increasing the efficiency of fluorescent concentrator systems

This study examines concepts for increasing the efficiency of fluorescent concentrator systems. Different system sizes and configurations are investigated in detail by external quantum efficiency measurements, light-beam-induced current maps and by I–V measurements. A photonic structure that serves as a bandstop reflection filter for light emitted from dyes in the fluorescent concentrator increases the system efficiency relatively by 20%. Such photonic structures are especially beneficial for larger systems. The combination of two fluorescent concentrators made with different dyes in one stack increases the system efficiency from 5.1% with only one dye to 6.7% for the stack.