The effect of barrier performance on the lifetime of small-molecule organic solar cells
In this work, we use different encapsulations to protect vacuum-evaporated small molecule organic solar cells with a simple p-i-i-stack for lifetime studies. Our devices use ZnPc and C60 as active materials. Lifetimes (T50) in a range from 300 h for un-encapsulated devices to 4000 h for glass-encaps...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Elsevier
2012
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| Summary: | In this work, we use different encapsulations to protect vacuum-evaporated small molecule organic solar cells with a simple p-i-i-stack for lifetime studies. Our devices use ZnPc and C60 as active materials. Lifetimes (T50) in a range from 300 h for un-encapsulated devices to 4000 h for glass-encapsulated have been observed. We use a model to distinguish between the water vapor transmission rate (WVTR) of the barrier and an additional WVTR of the aluminum top electrode. For all observed devices a loss of 50% of initial efficiency is observed when 10 mg m<sup>−2</sup> water entered the device. The losses are related to a reduction of short circuit current density only, whereas open circuit voltage and fill factor remains unaffected. We relate this to an interaction of the water molecules with C60. © 2011 Elsevier B.V. |
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