2-D hollow core photonic crystal fiber-type absorption layer for enhancement of efficiency and broad response in multi-junction solar cell

We present a numerical based approach to design a new 2-D hollow core photonic crystal (2-D HCPC) structure of hexagonal lattice arrangement with circular air holes on an Indium Tin Oxide (ITO) slab. We used this structure as an anti-reflective coating (ARC) layer on top of a multi-junction (GaP/InP/Si) solar cell. Apart from the ARC layer a GaAs PhC as back reflector (BR) is used in the MJSC structure. A unique approach by blending light trapping structures to enhance solar cell efficiency and light harvesting capabilities for wavelength beyond 750 nm is the goal of the present work. Under AM1.5G condition, the simulation results of the 2-D HC-PC structure as an absorption layer when incorporated on the MJSC structure led to an improvement of 6.38% in cell efficiency over the previously reported by the conventional/non-photonic MJSC structure. The absorption spectral response using the 2-D HCPC pattern on ITO as ARC on the MJSC is achieved beyond 1000 nm. An optimization study is also carried out by using InAs as core of the 2-D HCPC structure which resulted to an enhancement of cell efficiency by 9.34% as compared to the conventional/non-photonic MJSC structure.