| Work Detail |
Indian scientists have combined 2D perovskite solar cell technology with MXene materials to build a photovoltaic device with remarkable efficiency and open-circuit voltage. They say the cells new architecture is key to helping charge carriers move smoothly through the cells layers and reducing recombination losses.
Two-dimensional (2D) perovskites in the Dion-Jacobson (DJ) phase have attracted interest from the scientific community due to their stability under harsh environmental conditions and competitive performance in optoelectronic applications. However, solar cells based on DJ perovskites have shown comparatively inferior performance compared to their 3D counterparts.
Researchers at Chitkara University (India) have just developed a two-dimensional DJ perovskite solar cell by applying band gap techniques and using contacts based on a functionalized two-dimensional titanium carbide known as MXene.
MXenes compounds take their name from their graphene-like morphology and are fabricated by selectively etching specific atomic layers from a bulk crystal known as MAX. Recently, MXenes materials have shown promise for use in photovoltaic technology due to their unique optoelectronic properties, such as high charge carrier mobility, excellent metallic conductivity, high optical transmittance, and tunable work function (WF).
“In our work, we have carried out an extensive theoretical investigation using MXene contacts together with the 2D DJ perovskite (DJ-P), amalgamating the unique properties of both materials,” corresponding author of the research Rahul Pandey explained to pv magazine . “A key innovation of this research lies in the manipulation of the bandgap of the DJ-P layer through compositional tuning.”
The scientists explained that selecting a suitable electron transport layer (ETL) and hole transport layer (HTL) is key to achieving energy level alignment compatible with the DJ-perovskite layer and helping charge carriers move smoothly through the layers and reduce recombination losses.
To make the perovskite material more effectively absorb a wider range of wavelengths, band gap grading and MXenes were used to improve cell stability.
The researchers built the cell using an ETL made of phenyl-C61-butyric acid methyl ester (PCBM) and a HTL based on vanadium(V) oxide (V2O5). They then used two MXene materials known as Ta4C3F2 and T14N3 for the cell contacts and found that the optimal thickness of the perovskite absorber was 800 nm.
“We also varied the number of inorganic layers within the (PeDA)(MA)n-1PbnI3n+1 perovskite structure,” Pandey explained. “We then used linear, parabolic, beta and power-law grading profiles to optimize the composition of the DJ perovskite layer.”
Tested under standard lighting conditions, the device achieved a power conversion efficiency of 17.47%, an open-circuit voltage of 1.05 V, a short-circuit current density of 19.6 mA cm-2 and a fill factor of 84.25%. “The results demonstrate the potential of this novel approach to revolutionize 2D perovskite solar cell technology,” Pandey added, noting that the highest efficiency was achieved with the power-law profile.
The tests also showed that the linear profile achieved an efficiency of 16.62%, while the parabolic profile and beta profile achieved 16.62% and 17.30%, respectively.
The new cell concept is described in the study “ Tailored grading profiles for enhanced performance in Dion- Jacobson perovskite solar cells with MXene contacts,” recently published in Physica B: Condensed Matter . Looking ahead, the scholars say they want to investigate potential applications of these various grading profiles in 2D DJ-perovskite-based technologies. |
