Ultra-thin atomic-layer deposited alumina incorporating silica sol makes ultra-durable antireflection coatings

Abstract

We propose a strategy to make soda-lime glass maintain both high transparency and long-term durability in stringent high temperature and humid environments. Experiments reveal that the double-layered coatings with 110-nm-thick SiO2 and ultra-thin 25-nm- or 50-nm-thick Al2O3 layers, prepared by sol-gel dip coating and atomic layer deposition (ALD), respectively, exhibit the improvement of 5.88–6.32% in Tave (the average transmittance from the wavelength of 400–700 nm), as compared with that of the bare glass. On the other hand, the highly accelerated temperature and humidity stress test (HAST) confirms that both samples can sustain the 180 h test without any proven transmittance degradation, while the normalized Tave of the bare glass drastically drops to 43.1% of the initial value after the 108 h HAST. It implies that the ultra-thin Al2O3 films prepared by ALD, followed by dip-coated low-index layers such as SiO2 or nanostructured layer, can achieve both higher average transmittance and better durability, which would be of significance for the applications of ALD and dip coating techniques in the fields of consumer electronics, architecture with glass facades, and photovoltaics.

Multifunctional Antireflection Coatings Based on Novel Hollow Silica–Silica Nanocomposites

“…Regarding the practical use of such silica–silica nanocomposite SLAR coatings in PV modules, it is important to establish whether such coatings have high T PV , and whether they can withstand severe weather, especially high temperatures and humid environments. According to the module test protocol adopted by the International Electrotechnical Commission (IEC), IEC 61215, PV modules must be able to withstand 1000 h of damp heat tests (85 °C and 85% RH); this protocol is also typically used to evaluate the durability of AR coatings as well. ,, In our experiments, an accelerated-aging test, HAST, was performed. The acceleration factor of HAST relative to the damp heat test at 85 °C and 85% was estimated using the equation below A F = exp [ E a k true( 1 T normalu − 1 T normals true) + false( R H normalu n − R H normals n false) ] where AF is the acceleration factor, E a is the activation energy in eV, k is the Boltzmann constant, 8.6 × 10 –5 .…”

“…According to the module test protocol adopted by the International Electrotechnical Commission (IEC), IEC 61215, 48 PV modules must be able to withstand 1000 h of damp heat tests (85 °C and 85% RH); this protocol is also typically used to evaluate the durability of AR coatings as well. 16,49,50 In our experiments, an accelerated-aging test, HAST, was performed. The acceleration factor of HAST relative to the damp heat test at 85 °C and 85% was estimated using the equation below 51…”

A Universal Route to Realize Radiative Cooling and Light Management in Photovoltaic Modules

“…Besides the initial optical properties, the evolution under durability damp heat environments, that is, durability, is often investigated on conventional AR coatings . Herein, the harsh highly‐accelerated temperature and humidity stress tests (HAST) were performed on the sol–gel imprinted texture glass and the control, which was an accelerated and equivalent test to a 1000 h damp heat test (85 °C and 85% RH).…”