Encapsulation Epoxy for Photovoltaics and OLEDs
Materials, Solar Cell Prototyping Platform, Substrates and Fabrication
Overview | Specifications | Guide | References
A light-curable epoxy suitable for solar cell and LED encapsulation. Sets at wavelengths of up to 350 nm and is safe for use with most organic materials.
Curing wavelength: up to 350 nm
Usage:
- approx. 100 μl per standard sized substrate (10 ml ~ 100 standard substrates)
- approx. 600 μl per scale up sized substrate (60 ml ~ 100 scale up substrates)
Specifications
Viscosity | 250 to 360 cps @ 23°C |
Appearance | Colourless |
Cure schedule | 5 to 30 seconds at 250 to 350 nm at 10-100 mW/cm2 |
Refractive index | 1.4957 (at 589 nm) |
Specific gravity | 1.09 to 1.21 g/cc |
Cured Shore D Hardness | 85+ D |
Tensile strength | 8,000 psi |
Elongation | 3% |
Glass transition temperature | 138°C |
CTE | 50 x 10-6 |
Shelf life | 12 months at 23°C |
Dielectric constant | 3.94 @ 60 Hz @ 20°C |
Volume resistivity | 3.0 x 1014 Ω cm |
Datasheet
Ossila's E132 PV & LED Encapsulation Epoxy can be used as an adhesive for organic light-emitting diodes and organic photovoltaics without damaging the polymer or cathode. In conjunction with a glass coverslip, it can provide a robust barrier against ingress of oxygen and water, thus providing extended lifetimes for measurement and storage.
Curing can be achieved with UV or visible wavelengths as long as 350 nm, and at high intensities (100 mW/cm2) takes as little as 5 seconds. At lower intensities (such as those found in many lab-scale light boxes), curing time may be considerably longer (at up to 20 minutes).
Our encapsulation epoxy has been shown to encapsulate flexible substrates during an Innovate UK funded investigation.
PV & LED Encapsulation Process with Ossila Epoxy
Encapsulating the devices protects them against degradation by oxygen and moisture once removed from the glove box. True encapsulation for lifetimes of thousands of hours requires the use of glass welding technology and/or getter layers of calcium. However, we have developed a quick and effective way of encapsulating devices for lifetimes of several weeks or months under ambient conditions by using a specialised epoxy.
For small substrates (up to 2 cm2), place a single drop of epoxy dispensed from the end of a pipette onto the surface of the substrate, and place a glass cover-slip over the top. The encapsulation epoxy will then spread under the weight of the cover-slip over the course of a few seconds.
Check for voids and air bubbles under the cover-slip and if necessary gently press down on the coverslip to remove. Ensure the active area and metal cathode are covered.
Place in a light-box and expose until hardened.
Please also note: If used in a glove box, the encapsulation epoxy should be allowed to de-gas any absorbed oxygen/water for at least 24 hours prior to entering the glove box.
Video Guide - PV and LED Encapsulation
References
Radiative efficiency of lead iodide based perovskite solar cells, Henry Snaith et al., Scientific Reports, 4:6071, 2014
"Perovskites have already reached impressive power conversion efficiencies, and one of the main reasons for this is found in its high photovoltage which relates directly to its comparatively high ability to emit light."
Encapsulating light-emitting electrochemical cells for improved performance, Amir Asadpoordarvish et al., Appl. Phys. Lett., Vol. 100, 193508, 2012
"To summarize, we present a functional and scalable encapsulation procedure for LECs, which results in devices with a highly satisfactory ambient stability, as quantified by an uninterrupted lifetime of 490 h at a high brightness of >300 cd/m2 and a maximum current efficacy of 8.3 cd/A."