Lifetime of Organic Photovoltaics: Status and Predictions

Abstract

performance level, especially when considering large-scale mass-produced modules, is predicted to be signifi cantly lower. [ 8 ] Nevertheless, based on recent advances in the upscaling of OPV manufacture [9][10][11][12] it is reasonable to assume that the mass production of modules with an effi ciency of more than 5% is an achievable target today. Durability of OPV is however yet to be proven and demonstrated.Due to core architectural differences between OPV and inorganic technologies [ 13 ] the established testing standards of the latter are not applicable to the former. [ 1 ] Hence, for many years the stability testing of OPV has primarily been based on customized procedures that vary from one laboratory to another, generating incomparable data. [ 14 ] Moreover, due to the complexity of the OPV device architectures [ 15 ] and a multitude of aging mechanisms taking place at the same time [ 16 ] the aging curve of OPV often takes a complex shape, which is diffi cult to model, [ 14,17 ] thus making the identifi cation of a practical operational lifetime diffi cult or impossible. [ 18 ] As a result, even with a multitude of reported review articles discussing OPV stability [ 16,[19][20][21][22][23][24] at hand, it is still challenging to identify where the technology stands in terms of lifetime. To address this it is necessary to create a yardstick -a generic marker that allows accurate rating and comparison of the lifetime for OPV, and thus enabling the gauging of progress over time. An additional complication that has arisen due to the signifi cant improvements in OPV stability and durability in recent years is that the determination of OPV lifetimes has become an impractically long process, and establishing markers for both accelerated and real operational test conditions (if successful) would allow developing a prediction tool that could speed up the stability testing process and tackle this issue.The groundwork towards creating such a marker was laid in 2011 at the International Summit on OPV Stability (ISOS) where the ISOS testing guidelines were decided upon and described for OPV technologies. [ 18 ] These guidelines were primarily aimed at harmonizing testing procedures among different laboratories by offering a set of indoor and outdoor tests with controlled conditions. This has helped to reduce variations in the reported results, making the aging studies of different laboratories more comparable. [ 25 ] While the ISOS tests harmonized the test conditions, the questions of how to generically determine the lifetime from aging curves of diverse shapes, and how to build a technique for predicting the lifetime based on accelerated tests remained.The results of a meta-analysis conducted on organic photovoltaics (OPV) lifetime data reported in the literature is presented through the compilation of an extensive OPV lifetime database based on a large number of articles, followed by analysis of the large body of data. We fully reveal the progress of reported OPV lifetimes. Furthermore, a generic lifetime marker has...

Baselines for Lifetime of Organic Solar Cells

“…The data collection procedure is explained in detail elsewhere [11]. Briefly the articles were identified using the search engine ScienceDirect and exploring expressions based on different combination of words such as polymer, plastic, organic, solar cells, photovoltaics, stability, ageing and lifetime.…”

“…The latter was realized by following the steps outlined in the Table 1 and Figure 1 below. A more detailed explanation is provided elsewhere [11]. E0 -initial performance T0 -initial time T0 & E0 pair is either chosen at the first measurement point or if the curve has an initial increase followed by a reduction (such as the curve 3 in Figure 1 (a)) then T0 & E0 is set at the maximum point.…”

“…The works however continued and recently a manuscript was published by the same group, where the same statistical approach was utilized for analysing the entire literature related to stability of OPVs [11]. In the study, the authors collected analysed all the articles reported until…”

Toward High‐Temperature Stability of PTB7‐Based Bulk Heterojunction Solar Cells: Impact of Fullerene Size and Solvent Additive

“…[1][2][3][4][5][6][7] Despite these strong technological improvements, the insufficient stability is still a limiting factor for commercialization of PSCs. [8][9][10][11][12] Thus one of the key challenges of PSC technology is to overcome thermal instability of organic solar cells. Industrial standards demand for high-throughput roll-to-roll processing that usually requires several heating steps at high temperature to evaporate solvents from the printed layers.…”

Enhanced thermal stability of organic solar cells comprising ternary D-D-A bulk-heterojunctions

“…The stability of organic solar cells is often limited by a metastable bulk-heterojunction morphology, the diffusion of electrode or buffer layer components into adjacent layers, material decomposition through oxygen and water ingress, irradiation, mechanical stress or heat. [3][4][5] Yet, excellent thermal stability of the organic solar cells is a prerequisite for most future applications. Besides thermal stress when the solar cell is exposed to the sun, the devices may have to endure harsh conditions during fabrication, e.g., when manufacturing car roofs, tiles or façade elements, typically requiring lamination temperatures of 120°C for several hours.…”