Recent Applications of Antireflection Coatings in Solar Cells

Abstract

The antireflection coating (ARC) suppresses surface light loss and thus improves the power conversion efficiency (PCE) of solar cells, which is its essential function. This paper reviews the latest applications of antireflection optical thin films in different types of solar cells and summarizes the experimental data. Basic optical theories of designing antireflection coatings, commonly used antireflection materials, and their classic combinations are introduced. Since single and double antireflection coatings no longer meet the research needs in terms of antireflection effect and bandwidth, the current research mainly concentrates on multiple layer antireflection coatings, for example, adjusting the porosity or material components to achieve a better refractive index matching and the reflection effect. However, blindly stacking the antireflection films is unfeasible, and the stress superposition would allow the film layer to fail quickly. The gradient refractive index (GRIN) structure almost eliminates the interface, which significantly improves the adhesion and permeability efficiency. The high-low-high-low refractive index (HLHL) structure achieves considerable antireflection efficiency with fewer materials while selecting materials with opposite stress properties improves the ease of stress management. However, more sophisticated techniques are needed to prepare these two structures. Furthermore, using fewer materials to achieve a better antireflection effect and reduce the impact of stress on the coatings is a research hotspot worthy of attention.

Bridging the gap between surface physics and photonics

“…To reduce reflection for solar cells and photodiodes, antireflection coatings (ARCs) [52][53][54] and surface texturing techniques [55][56][57][58][59][60][61] are designed. By carefully engineering the refractive index of the surface, the reflection can be minimized, allowing more light, particularly in the wavelength range of interest, to pass into the semiconductor material and be absorbed, resulting in higher device performance and new applications.…”

Periodic Al2O3 Nanohole Arrays on MgO (100) for a Low-Reflectivity External Cavity Fabry–Pérot Interferometer

“…Currently, multilayer composite thin-film coating is the most common approach to achieving AR. 10,11 However, the stability of the multilayer structures may be insufficient for hightemperature applications. With the development of photonics technology, interfaces can be designed with periodic subwavelength-scale structures, such as pillars, holes, pyramids, and cones.…”

“…Currently, multilayer composite thin-film coating is the most common approach to achieving AR. , However, the stability of the multilayer structures may be insufficient for high-temperature applications. With the development of photonics technology, interfaces can be designed with periodic subwavelength-scale structures, such as pillars, holes, pyramids, and cones. − The refractive index on both sides of the interface can gradually change using relief structures, avoiding light loss or reflection caused by abrupt refractive index changes without increasing the influence of diffraction.…”

New multilayer film photonic crystal grating multilayer anti-reflection layer for visible-near-infrared solar cells

“…The existing research on ARL is divided into two main categories, namely, membrane structure and micronano-optical structure [11,12]. Wang et al theoretically and experimentally concluded that the experimental porous SiO 2 and MgF 2 double-layer anti-reflection can improve the short-circuit current density of siliconbased stacked cells, and the ARL has good anti-reflection properties in the range of 400-1200 nm [13].…”