Impact of distributed Bragg's reflectors and nanogratings in thin film silicon solar cells

Photonic crystals possess periodic modulation of higher refractive index contrast which brings a unique photonic band gap. In this work, thin-film silicon solar cell optical performance was studied by the finite-difference time-domain (FDTD) method. The distributed Bragg reflector (DBR) and nanogratings are integrated as a backside reflector, which endorses the photonic modes in the silicon solar cell. The light trapping scheme plays a pivotal role in solar cells due to the limited absorption in the higher spectral region. For that, various silicon solar cell structures are investigated for better light absorption using photonic ray theories with numerical simulations. This result indicates the combination of DBR and nanogratings is capable and yielded a high relative enhancement of 59% as compared with the reference cell which was endorsing the Fabry–Perot resonance and guided-modes in photovoltaic devices. These results show promise for designing thin film silicon solar cells with enhanced light absorption.