Researchers at India's Chitkara University Institute of Engineering and Technology have developed 2D perovskite solar cells with MXene materials to build a PV device with remarkable efficiency and open-circuit voltage. The scientists claim the new cell architecture can help charge carriers move smoothly through the cell layers and reduce recombination losses.
The team's 2D DJ perovskite solar cell implemented bandgap grading techniques and use contacts based on a functionalized two-dimensional titanium carbide known as MXene. MXenes are compounds that take their name from their graphene-like morphology and are made via selective etching of certain atomic layers from a bulk crystal known as MAX. Recently, MXenes materials have shown promise for use in PV technology due to their unique optoelectronic properties, such as their large charge carrier mobility, excellent metallic conductivity, high optical transmittance, and tunable work function (WF).
The team conducted a comprehensive theoretical investigation by employing MXene contacts in conjunction with the 2D DJ perovskite (DJ-P), combining the unique properties of both materials. The scientists said that a key innovation of this research lies in the manipulation of the DJ-P layer's bandgap through compositional adjustments. They explained that the selection of an appropriate electron transport layer (ETL) and hole transport layer (HTL) is key to achieving compatible energy level alignment with the DJ-perovskite layer and helping charge carriers move smoothly through the layers and reduce recombination losses.
The scientists built the cell with an ETL made of phenyl-C61-butyric acid methyl ester (PCBM) and an HTL relying on vanadium(V) oxide (V2O5). They then used two MXene materials known as Ta4C3F2 and T14N3 for the cell contacts and found the optimal thickness of the perovskite absorber was 800 nm.
The team also varied the number of inorganic layers within the (PeDA)(MA)n-1PbnI3n+1 perovskite structure and then used linear, parabolic, beta, and power law grading profiles to optimize the DJ perovskite layer's composition.
Tested under standard illumination 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%.
These results demonstrate the potential of the novel approach to advance 2D-perovskite solar cell technology. 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.
