Photon Management Structures Based on Interference Lithography and Nanoimprint Processes
Since micro- and nanostructures for photon management are of increasing importance in novel highefficiency solar cell concepts, structuring techniques with up-scaling potential play a key role in their realization. Interference lithography and Nanoimprint processes are presented as technologies for origination and replication of fine-tailored photonic structures on large areas. With the interference pattern of two or more coherent waves, a wide variety of structures can be generated on areas of up to 1.2 x 1.2 m². In combination with subsequent nanoimprint steps, the industrially feasible production of elaborate structures is possible. After the description of the basic technologies, four application examples are presented: (1) honeycomb structures for the front side texturization, (2) diffractive back side gratings for absorption enhancement in the spectral region near the band gap of silicon, (3) periodic and aperiodic imprinted structures as substrates for TCO deposition, and (4) plasmonic metal nanoparticle arrays manufactured by combined imprint and lift off processes.