Utilization of CaF<sub>2</sub>/ITO Double‐Layer Anti‐Reflective Coating for Increasing the Efficiency in Rear Emitter SHJ Solar Cells
Muhammad Aleem Zahid, Muhammad Quddamah Khokhar, Youngkuk Kim, Junsin Yi
Abstract
Abstract A method to minimize optical losses in the front side of rear emitter silicon heterojunction (SHJ) solar cells by applying double‐layer antireflection coating (DLARC) has been examined. The primary aim is to increase the short circuit current density ( J sc ) using DLARC that is associated with the cell's absorbance. The optical and electrical properties of single‐layer antireflection coating (SLARC) are studied and compared with calcium fluoride (CaF 2 )/Indium tin oxide (ITO) DLARC.OPAL 2 is utilized as a simulation tool to increase the optical properties of CaF 2 /ITO DLARC, and the experimental result verifies its validity. ITO is deposited using sputter system while thermal evaporator is utilized to deposit CaF 2 to make DLARC. The SHJ solar cell having DLARC demonstrates the average reflection of 6.55% which is 31.7% less than SLARC, that is 9.59% for the wavelength range of 300 to 1100 nm. The fabricated textured solar cell with CaF 2 /ITO DLARC shows enhancement in external quantum efficiency from 76.89% to 81.06%. It also indicates an improvement in J sc to 40.83 mA cm ‐2 from 39.91 mA cm –2 and having a conversion efficiency of >21% when compared with that of ITO SLARC.