Graphene-Based Materials for Organic Photovoltaic Devices

Organic photovoltaic devices promise lightweight, flexible and low-cost solar energy solutions, yet their widespread adoption has been held back by limited conversion efficiencies and operational stability. Graphene-based materials, encompassing pristine graphene, graphene oxide (GO), reduced graphene oxide (rGO) and graphene quantum dots (GQDs), offer exceptional electrical conductivity, high optical transparency and superior mechanical robustness. When deployed as transparent electrodes, interfacial layers, charge transport layers or active-layer additives, these materials can optimise energy-level alignment, facilitate charge extraction and suppress recombination. In bulk heterojunction architectures, graphene derivatives improve phase separation between donor and acceptor phases, enhancing exciton dissociation and carrier mobility. Moreover, the tunable surface chemistry of GO and GQDs enables fine control of work function and film morphology, while rGO layers impart barrier properties that impede moisture ingress and photo-oxidative degradation. Collectively, these attributes contribute to measurable gains in power conversion efficiency and device longevity, positioning graphene-based materials at the forefront of next-generation organic solar cell research.

Research from Nature Portfolio

Recent studies have demonstrated that incorporating a graphene oxide/PEDOT:PSS double-deck hole transport layer in bulk heterojunction devices yields marked improvements in power conversion efficiency. The bilayer design achieves better energy-level matching and reduced series resistance compared with single-component interlayers, leading to higher short-circuit currents and fill factors. Importantly, the GO/PEDOT:PSS composite also acts as a protective barrier against moisture and electrode corrosion, significantly enhancing device operational stability without complex encapsulation strategies.

Graphene-Based Materials for Organic Photovoltaic Devices publication trend

The graph below shows the total number of articles in graphene-based materials for organic photovoltaic devices across all publications each year (not limited to Nature Index journals).

Technical terms

Graphene oxide (GO): Stacked sheets of graphene functionalised with oxygen-containing groups to enhance solubility and tune electronic properties.

Reduced graphene oxide (rGO): Graphene oxide with partial removal of oxygen groups, restoring electrical conductivity closer to pristine graphene.

Bulk heterojunction: A blend of donor and acceptor materials forming interpenetrating nanoscale networks to facilitate exciton dissociation and charge transport.

Hole transport layer (HTL): Material layer that selectively extracts and transports positive charge carriers (holes) to the electrode.

Electron transport layer (ETL): Material layer that selectively extracts and transports negative charge carriers (electrons) to the electrode.

Power conversion efficiency (PCE): Ratio of electrical energy output to incident solar energy, expressed as a percentage.

Work function: Minimum energy required to remove an electron from a material’s surface, critical for interface energy alignment.

References

1. Significantly improved photovoltaic performance in polymer bulk heterojunction solar cells with graphene oxide /PEDOT:PSS double decked hole transport layer. Scientific Reports (2017).
2. Polymer-nanocarbon composites: a promising strategy for enhanced performance of organic solar cells. Emergent Materials (2023).
3. Fluorinated Reduced Graphene Oxide as an Efficient Hole-Transport Layer for Efficient and Stable Polymer Solar Cells. ACS Omega (2017).
4. Stability of graphene-based heterojunction solar cells. RSC Advances (2015).