Combined characterization techniques to understand the stability of a variety of organic photovoltaic devices: the ISOS-3 inter-laboratory collaboration

Abstract

This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPVs) devices prepared by leading research laboratories. All devices have been shipped to and degraded at the Danish Technical University (DTU, formerly RISO-DTU) up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work we present a summary of the degradation response observed for the NREL sample, an inverted OPV of the type ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag/Al, under full sun stability test. The results reported from the combination of the different characterization techniques results in a proposed degradation mechanism. The final conclusion is that the failure of the photovoltaic response of the device with time under full sun solar simulation, is mainly due to the degradation of the electrodes and not to the active materials of the solar cell.

Spatial degradation mapping and component-wise degradation tracking in polymer–fullerene blends

“…[5,6]fullerene) and C70 (C70-Ih) [5,6]fullerene) from Aldrich, and ICBA (1',1'',4',4''-tetrahydrodi [1,4]methanonaphthaleno [5,6]fullerene-C60) from Plextronics.…”

“…Extensive work has been directed towards understanding these degradation mechanisms and developing new materials and geometries that can increase device lifetime. 3,5,6 Hereby, device lifetime has been observed to increase from days to months and years in recent years, and lifetimes in the range of 1-2 years are now reached with the range of 3-5 years being realistic in the near future. 7,8 Conventionally, the device stability is assessed by exposing the functioning device to simulated sunlight while measuring the electrical performance through IV-characterization.…”

Influence of the Hole Transporting Layer on the Thermal Stability of Inverted Organic Photovoltaics Using Accelerated-Heat Lifetime Protocols

“…6 Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is the most common material used as the hole-transporting layer (HTL) in both architectures. It is known that because of its hygroscopic nature, ingress of moisture and oxygen from the edges into the device can cause degradation.…”

“…In the inverted structure, 4 , 5 the use of an air-stable metal such as silver results in enhanced lifetime compared with normal structured OPVs, which are limited in stability mainly because of the oxidation of the metals such as calcium or aluminum. 6 Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is the most common material used as the hole-transporting layer (HTL) in both architectures. It is known that because of its hygroscopic nature, ingress of moisture and oxygen from the edges into the device can cause degradation.…”

“…Photocurrent mapping measurements provide degradation images at 65 °C at various points in time. Second, different electrode configurations are investigated for our reference poly(3-hexylthiophene): [6,6]phenyl C 71 -butyric acid methyl ester (P3HT:PC[70]BM) polymer/fullerene active layer. Using combinations of two interlayersMoO 3 and PEDOT:PSSat the top electrode of P3HT:PC[70]BM-based devices, the device degradation is attributed primarily to the interface between the active layer and MoO 3 and secondarily to that between MoO 3 and Ag.…”