The resurgence of organic photovoltaics

Abstract

Several advances were reported in the field of organic photovoltaics in the last two years. Development and application of non-fullerene acceptors in particular has injected new life into the field. Exploitation of such materials in ternary blends and tandem solar cell structures has in fact enabled record high efficiencies >15%, thus paving the way towards commercialisation. Introduction:Organic semiconductors (OS) rapidly became a success story for light-emitting diodes and then displays, now found in a plethora of commercial applications with further current focus on extending their performance in the near infra-red [1,2]. On the other hand, organic photovoltaics (OPVs) have lagged behind due to their limited efficiencies. Recently, advances in OPV research led to the fabrication of record high 17.3% [3••] efficient solar cells, thus demonstrating a potentially bright future for OPVs as well. The key competitive advantage of OPVs is their solutionprocessability which can offer low-cost fabrication of flexible devices over large areas [4]. They can also be semitransparent, and therefore penetrate into niche markets such as photovoltaic windows [5,6]. Indeed, OPVs have already shown excellent potential especially for wearable technologies and indoor energy generation [7,8].

Air-stable ternary organic solar cells achieved by using fullerene additives in non-fullerene acceptor-polymer donor blends

“…6,[9][10][11][12] There have also been significant advances in understanding degradation mechanisms and improving the ambient stability of OSCs. [13][14][15] However, the stability of binary blends based on NFAs remains insufficient for commercialization. Among the reported stabilization strategies of OSC cells and modules, 16 the incorporation of additives is a viable avenue to further enhance the ambient stability of OSCs.…”

Inverted organic photovoltaics with a solution-processed Mg-doped ZnO electron transport layer annealed at 150 °C

“…1 Low temperature processing allows for significant energy savings that makes manufacturing more sustainable 2 and reduces cost that can, in turn, lower the barriers to market entry. 3 For the case of organic semiconductors (OS) in particular, a key opportunity to penetrate the market is via niche applications 4,5 which in turn usually require the use of flexible substrates. 6 In most cases such substrates are not compatible with “high temperatures” ( i.e.…”

“…[23][24][25] Nevertheless, sol-gel ZnO drawbacks include a poor interfacial contact with the bulk heterojunction active layer and surface defects that can act as electron trap sites and thus affect device performance. In addition, given the large number of different acceptor materials that have been developed for use in active layers of OPVs, 5 having some degree of control over the properties of the ZnO ETL such as its work function or conductivity, so as to tailor it for the specic active layer blend has become crucial. To this end, three main strategies have been developed over time to remedy the shortcomings of ZnO ETLs and to enable control of its properties.…”

High Figure-of-Merit Transparent Copper–Zinc Oxide Window Electrodes for Organic Photovoltaics

“…The low cost associated with processing organic semiconductors by printing, together with the low processing temperature and color tuneability make organic photovoltaics (OPVs) attractive for a diverse range of applications (Kippelen et al, 2009;Ierides et al, 2019). The flexibility and light weight of OPVs supported on flexible plastic substrates also enables integration into wearable electronics, roofing, automobile and building related applications where conventional rigid photovoltaics are not suitable (Mohammad Bagher, 2014;Stoppa and Chiolerio, 2014;Zamarayeva et al, 2017;Meng et al, 2018;Cui et al, 2019), as well as enabling compact storage for transportation.…”