Enhanced light absorption of ultrathin crystalline silicon solar cells via the design of front nanostructured silicon nitride

In contrast to traditional approach using Si nanotexture, we propose and investigate the light-trapping enhancement of ultrathin c-Si cells via the design of front nanostructured antireflective layer by using the finite-difference time-domain method, where four nanostructures of nanorod hole (NRH) arrays, nanosquare hole (NSH) arrays, inverted nanocone hole (INCH) arrays, and inverted nanopyramid hole (INPH) arrays are applied to silicon nitride for comparison. Via the simulations and optimizations, it is found that the solar cells with design of inverted nanocone hole arrays can produce the highest short-circuit photocurrent density of 29.46 mA/cm2 resulting in an enhancement of 29.32% compared with the control group (with 67 nm Si3N4). Furthermore, when the optimal cells are integrated with back silver, a photocurrent density of 32.20 mA/cm2 can be achieved, offering an additional benefit of 2.08 mA/cm2 compared with 30.12 mA/cm2 using back aluminum.