Photovoltaic Performance of Two-Dimensional Materials

Two-dimensional (2D) semiconductors such as transition metal dichalcogenides and graphene derivatives have emerged as transformative platforms for next-generation solar energy conversion. Their atomically thin form factors enable unprecedented specific power, while high optical absorption coefficients and tunable band gaps support efficient light harvesting across the visible spectrum. Van der Waals assembly of disparate 2D layers yields atomically sharp heterojunctions in which band-gap engineering and interface design can be precisely controlled. Advances in large-area synthesis and transfer techniques now allow scalable device fabrication on both rigid and flexible substrates. Key challenges remain in charge-carrier recombination at defects, Fermi-level pinning at contacts and the integration of robust doping schemes. Recent progress in transparent conductive contacts, anti-reflection coatings and encapsulation strategies has led to steady improvements in power conversion efficiencies, bringing 2D photovoltaics closer to practical applications in aerospace, wearable electronics and building-integrated solar modules. Ongoing efforts focus on understanding non-radiative recombination pathways, optimising light-trapping structures and exploiting hybrid architectures that combine 2D films with organic polymers or bulk semiconductors. Together, these developments underscore the global significance of 2D materials as ultralight, flexible and high-performance photovoltaic technologies.

Research from Nature Portfolio

Recent studies have established the fundamental efficiency limits of ultrathin transition metal dichalcogenide (TMD) solar cells by incorporating both radiative and non-radiative recombination mechanisms into detailed balance models. These analyses predict that single-junction devices with absorber thicknesses of 50 nm could achieve up to 25 per cent power conversion efficiency under standard illumination, given current material quality. Complementary experimental work on flexible TMD solar cells has addressed contact-induced Fermi-level pinning through the use of transparent graphene electrodes, while MoOx capping layers provide passivation, doping and anti-reflection. A non-damaging direct-transfer technique onto lightweight polymer substrates has yielded record values of 5.1 per cent efficiency and 4.4 W g–1 specific power, demonstrating parity with established thin-film technologies and potential for ultralight, conformable energy harvesters.

Photovoltaic Performance of Two-Dimensional Materials publication trend

The graph below shows the total number of articles in photovoltaic performance of two-dimensional materials across all publications each year (not limited to Nature Index journals).

Technical terms

Van der Waals heterojunction: Interface between two atomically thin materials bonded by weak interlayer forces, enabling defect-free junctions.

Power conversion efficiency (PCE): Percentage of incident solar energy converted into electrical power by a photovoltaic device.

Specific power: Electrical power output per unit mass, important for weight-critical applications such as aerospace.

Shockley-Read-Hall recombination: Non-radiative carrier loss via defect states within the band gap that reduces photovoltaic performance.

Band gap engineering: Deliberate tuning of electronic energy levels through layer thickness or composition to optimise light absorption and charge separation.

References

1. The Influence of MoS2 Thickness on the Efficiency of Solar Energy Conversion in TiO2/MoS2/P3HT Cells. Progress in Photovoltaics Research and Applications (2024).
2. Efficiency limit of transition metal dichalcogenide solar cells. Communications Physics (2023).
3. High-specific-power flexible transition metal dichalcogenide solar cells. Nature Communications (2021).
4. Large-Area, High-Specific-Power Schottky-Junction Photovoltaics from CVD-Grown Monolayer MoS2. ACS Applied Materials & Interfaces (2022).
5. Structural, electrical and optical properties of hetrostructured MoS2/ZnO thin films for potential perovskite solar cells application. Journal of Materials Research and Technology (2022).