Ray Tracing of Aluminum Nitride as Anti-Reflective Coating on Silicon for Photovoltaic Devices

III-nitride materials have attracted wide interests for optoelectronic and electronic applications due to their unique and tunable semiconducting and optical properties. Aluminum nitride (AlN) exhibits an ultra-wide bandgap of 6.2 eV and wide transparency window from ultraviolet to mid-infrared, making it a promising candidate as an anti-reflective coating (ARC) material on silicon for photovoltaic (PV) devices. In this work, ray tracing is utilized to investigate the optical properties of AlN ARC on 150 [Formula: see text]m-thick c-Si absorber. AlN with thicknesses of 60–90 nm are studied and the effects towards light absorption (within 300–1200 nm wavelength region) and short-circuit current density (J SC ) of the solar cell are analyzed. In the ray tracing, planar c-Si absorber without an ARC is used as a reference. The reference condition exhibits weighted average reflection (WAR) of 39.8% within the 300–1200 nm wavelength region with J SC of 25.49 mA/cm 2 . AlN with 80 nm is found to be the optimum ARC thickness, which leads to the enhanced broadband absorption with WAR of 19.7% within the spectral region. This thickness represents the highest J SC achieved in this work (35.71 mA/cm 2 ).