The performance of solar cells (SCs) can be enhanced significantly by employing 2D photonic crystals (2D-PCs). They can either be used as omnidirectional, broadband antireflection coatings (ARCs) or applied to thin-film SCs (where PC effects are much more significant than in generic SCs). Although multilayer ARCs are commonly used, problems related to material selection, thermal mismatch, sensi...