کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
79063 | 49347 | 2011 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Influence of the hole-transport layer on the initial behavior and lifetime of inverted organic photovoltaics Influence of the hole-transport layer on the initial behavior and lifetime of inverted organic photovoltaics](/preview/png/79063.png)
The inverted organic photovoltaic (OPV) device architecture represents an important advancement due to the relative environmental stability of the electron transport layer (ETL) and hole-collecting contact. We investigated the initial and long-term behavior of inverted devices to identify changes taking place at the Ag hole-collecting contact. We show that efficient hole collection can be obtained after modifying the Ag contact by thermal annealing, long-term exposure to ambient atmosphere, or employing a high work function organic hole-transport layer (HTL). We find that whether or not the device employs an organic HTL, degradation of the photocurrent initially follows a simple exponential decay. After prolonged illumination (>500 h), devices with an organic HTL fail catastrophically due to a precipitous drop in photocurrent. Based on evidence for pinhole-induced degradation observed in photocurrent maps, we propose a nucleation and island growth mechanism and a model for the photocurrent behavior employing a modified Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation. Devices that do not contain an HTL appear to degrade by a mechanism other than pinhole ingress resulting in a more uniform degradation of the photocurrent across the active area.
Figure optionsDownload as PowerPoint slideResearch highlights
► We monitor initial and long-term behavior of illuminated inverted P3HT:PCBM devices.
► Initial improvement arises due to evolution of the active layer-Ag interface.
► Two modes of failure are found to depend on modification of the hole-collecting contact.
► We propose a nucleation and island growth mechanism to model catastrophic current loss.
Journal: Solar Energy Materials and Solar Cells - Volume 95, Issue 5, May 2011, Pages 1382–1388