The solar energy industry strives to produce more and more efficient and yet cost effective photovoltaic (PV) panels.
Integration of specific micro/nano optical structures on the top surface of the PV panels is one of the efficient ways to
increase their PV performance through enhancing light trapping and in-coupling. In this study, periodic triangular
gratings (PTGs) in polymethyl methacrylate (PMMA) were numerically simulated and optimized. The goal of this study
is to enhance the ability of solar panels to convert maximum obtainable amount of solar energy by improving the optical
in-coupling of light to PV material. Initial optical simulation results shown that a flat PV panel (without any enhancing
micro-optical structures) exhibits an average incident light power of 0.327 W over a range of the incident light angles
between 15º and 90º. Introduction of the PTG allows capturing the incoming sunlight and reflecting it back onto the PV
material for a second or more chances for absorption and conversion into electricity. The light trapping and redirection is
achieved through the total internal reflection (TIR) phenomenon. Geometry of the PTG was initially optimized with
respect to an incident sunlight orientation of 15º, 30º, 45º, 60º, 75º, and 90º. Optical performance of the particular
optimized PTGs was analyzed over daylight conditions and several optical parameters, such as average incident power
and intensity, were calculated when sunlight orientation angle was changing from 15º to 90º. By adding the PTG
optimized for 15º incidents light, an average incident power of 0.342 W was achieved (4.6% improvement of optical
performance). Functional PTG prototypes were fabricated with optical surface quality (below 10 nm Ra). The simulation
results allow understanding how the overall daytime photovoltaic performance of solar panels can be improved.
2-D slab photonic crystal multiple line defect waveguides have been designed for optical power splitting
application which has numerous applications in photonic integrated circuit. The operation of the device is
based on multimode interference effects and self-imaging phenomenon. The proposed structure consists of
multiple photonic crystal line defect waveguides which are formed in the Γ-K direction by removing several
entire rows of air-holes. The adjacent photonic crystal waveguides are separated by a row of air-holes. In this
scheme a 1×3 power splitter is designed which involves three photonic crystal line defect waveguides
multimode region, five photonic crystal line defect waveguides multimode region and one separation region.
The entire structure is verified by 3-D finite difference time domain method. The transmitted power achieved
at each output channel i.e. CH1, CH2 and CH3 are about 26.3%, 26.8% and 26.3% respectively. The total
transmitted output power of 1×3 power splitter is 79.4% at target wavelength of 1.55μm.