Silica Aerogel Thin Film on Improving Solar Cell Efficiency

TL;DR

This study demonstrates that hydrophobic silica aerogel thin films, synthesized under ambient conditions, can enhance solar cell efficiency by reducing reflection and improving light absorption, offering a cost-effective method for photovoltaic performance improvement.

Contribution

The paper introduces a novel ambient-pressure synthesis method for hydrophobic silica aerogel films applied to silicon solar cells, showing improved photovoltaic efficiency.

Findings

Increased output voltage with aerogel coating

Enhanced charge transport and conversion efficiency

Low refractive index improves light trapping

Abstract

Silica aerogels are nanoporous materials with exceptional optical and physical properties, making them promising candidates to enhance solar cell efficiency as antireflective coatings. This study synthesized hydrophobic silica aerogel thin films under ambient conditions and characterized their porous structure, surface morphology, and optical performance. The films were deposited on monocrystalline silicon solar cells to assess their impact on photovoltaic properties. A two-step acid/base catalyzed sol-gel process was utilized, followed by solvent exchange and surface modification with trimethylchlorosilane. Structural analysis via SEM revealed successful deposition of crack-free films when aging occurred in an ethanol environment. The aerogel displayed considerable specific surface area (115 m2/g), porosity (77.92%), and surface roughness (55-78%) along with a low refractive index (1.05), benefiting light harvesting. Preliminary solar testing showed increased output voltage with a 0.2 mm aerogel coating versus a bare cell. Further IV measurements demonstrated enhanced charge transport and conversion efficiency for the treated cell. The antireflective and light-trapping effects of aerogel appear to improve photon absorption. This initial research validates the potential of ambient pressure-synthesized hydrophobic silica aerogels to increase the performance of silicon photovoltaics cost-effectively. Further optimization of film thickness and morphology could realize higher efficiency gains.