Research paper: Stabilizing Perovskite Solar Cells at 85 °C via Additive Engineering and MXene Interlayers
This research focuses on stabilizing Perovskite Solar Cells (PSCs) at 85\text{ °C} using additive engineering and 2D Ti3C2 MXene interlayers. The study compared reference devices (REF) with modified devices (MOD) incorporating 3-phosphonopropionic acid (H3PP) in the perovskite bulk and a H3PP-functionalized MXene interlayer.
Methods employed included Maximum Power Point Tracking (MPPT) operational stability testing (ISOS-L3 protocol), complemented by in situ X-ray diffraction (XRD), Electrochemical Impedance Spectroscopy (EIS), photoluminescence (PL), and Transmission Electron Microscopy (TEM).
Key results revealed a reversible formation of an amorphous "carbon rich" surface shell surrounding the perovskite grains in REF samples after operation at 85 °C and ∼100 mW cm−2 illumination. This material formation was linked to a sharp voltage drop, a decrease in perovskite shunt resistance (Rpsh), and a reduction of the low frequency time constant (τLF) by between one and three orders of magnitude, indicating increased ionic conductivity. The MOD devices, incorporating the additive and interlayer, successfully delayed this degradation, mitigating recombination and shunt losses. The PSC lattice exhibited thermal expansion, increasing the lattice parameter by ∼0.02 A˚ upon heating from 27 °C to 85 °C.
The significance lies in using simultaneous in operando structural and performance monitoring in full PSC devices at 85 °C and illumination stress, providing a critical framework for stabilizing PSCs for commercial standards.
How Fluxim´s R&D Tools were used
The study utilized three Fluxim tools: LITOS LITE, PAIOS, and SETFOS.
LITOS LITE was the commercial setup employed for MPPT operational stability analysis (ISOS-L3 protocol) of PSCs at 85 °C and ∼100 mW cm−2 illumination over periods exceeding 20 h. This tracked the Power Conversion Efficiency (PCE), VMPP, and JMPP evolution to quantitatively assess the stability enhancement provided by the MXene/H3PP modifications.
PAIOS performed the Electrochemical Impedance Spectroscopy (EIS) measurements. It collected impedance amplitude of 20.0 mV across a frequency sweep from 4 MHz to 0.08 Hz at the open circuit voltage (VOC) under a logarithmic array of light intensities. This was critical for quantifying changes in recombination (Rrec), perovskite shunting (Rpsh), and the low frequency time constant (τLF), which revealed increased ionic conductivity and shunt paths post-stress.
SETFOS was used to perform drift diffusion simulations. These simulations were important for supporting the hypothesis that the observed low frequency EIS shift was caused by modifying the cation mobility (simulated from E-4 to E2 cm2/Vs), rather than cation density changes.
Why this research matters
This research matters because it tackles one of the biggest barriers to commercializing perovskite solar cells—their instability at high temperatures. It’s the first study to monitor both structural and electrical behavior in operando at 85 °C, revealing how heat causes reversible formation of a carbon-rich amorphous shell and interfacial strain that degrade performance. Crucially, it demonstrates that additive engineering (H₃PP) and MXene interlayers can prevent these effects, providing a clear framework for designing more stable, commercially viable PSCs.
Citation
Baumann, F., Padilla-Pantoja, J., Caicedo-Roque, J. M., Karimipour, M., Vahedigharehchopogh, N., Santiso, J., Ballesteros, B., Miranda Gamboa, R. A., Tian, Z., Raga, S. R., & Lira-Cantú, M. (2025). Stabilizing perovskite solar cells at 85 °C via additive engineering and MXene interlayers. EES Solar. Royal Society of Chemistry. https://doi.org/10.1039/d5el00104h