Optimal light trapping in ultra-thin photonic crystal crystalline silicon solar cells

摘要: Using thin films of crystalline silicon to make solar cells reduces the cost by reducing amount material needed and allowing poorer quality with shorter carrier diffusion lengths be used. However, indirect band gap of silicon requires that a light trapping approach used maximize optical absorption. Here, photonic crystal (PC) based is harvesting in 400 nm-thick layer tuning coupling strength of incident radiation quasiguided modes over broad spectral range. The structure consists double PC. We show an enhancement maximum achievable photocurrent density from 7.1 mA/cm 2 for unstructured film 21.8 mA/cm structured normal incidence. This value approaches limit 26.5 mA/cm , obtained using Yablonovitch same volume active material.