Figure 5: (a) Photon number spectrum of the AM1.5 solar irradiations (AM()). (b) Absorption efficiency spectrum (). (c) Absorbed photon number spectrum (APNS). (d) Total enhancement of absorbed photon number (TEAPN) inside the Si layer over the entire solar spectrum versus the different array periods. The subscripts “TE” and “TM” in (a) and (b) represent different polarizations for the proposed solar cells with a period of 550 nm. The subscript “B” corresponds to the bared Si film with a thickness of 80 nm.