Strain Modulation for Light‐Stable n–i–p Perovskite/Silicon Tandem Solar Cells

Abstract

Perovskite/silicon tandem solar cells are promising to penetrate photovoltaic market. However, the wide‐bandgap perovskite absorbers used in top‐cell often suffer severe phase segregation under illumination, which restricts the operation lifetime of tandem solar cells. Here, a strain modulation strategy to fabricate light‐stable perovskite/silicon tandem solar cells is reported. By employing adenosine triphosphate, the residual tensile strain in the wide‐bandgap perovskite absorber is successfully converted to compressive strain, which mitigates light‐induced ion migration and phase segregation. Based on the wide‐bandgap perovskite with compressive strain, single‐junction solar cells with the n–i–p layout yield a power conversion efficiency (PCE) of 20.53% with the smallest voltage deficits of 440 mV. These cells also maintain 83.60% of initial PCE after 2500 h operation at the maximum power point. Finally, these top cells are integrated with silicon bottom cells in a monolithic tandem device, which achieves a PCE of 26.95% and improved light stability at open‐circuit.

A Universal Grain “Cage” to Suppress Halide Segregation of Mixed-Halide Inorganic Perovskite Solar Cells

“…So far, some mechanisms have been found to explain the thermodynamic driving force for halide segregation, such as compositional/electronic structure-linked free energy difference, polaron formation and strain effect, , bandgap reduction, hole injection and accumulation, local electric field, and anion vacancies, which provide the guidelines for rationally designing materials to solidify the soft perovskite lattice. The mutual principle for all the scenarios is to shut down the ion-to-vacancy or ion-to-ion migration channels by considering the vacancy-assisted migration process, for example, eliminating anion vacancies or lowering dimension with large organic cations. , As evidenced by the recent study on Pb 2+ /Pb 0 and I – /I 3 – redox chemistry, the iodide ions suffer from grain-to-boundary diffusion and then nucleate at grain boundaries to form an iodide-rich phase .…”

High-performance flexible and self-powered perovskite photodetector enabled by interfacial strain engineering

“…3d. Recent studies have well illustrated that the residual tensile strain in a perovskite film leads to instability, 40–42 and hence releasing the lattice strain by PDCBT also enhances the perovskite film stability.…”

Sandwiched Structure Design for Perovskite Solar Cells with Improved Folding and Environmental Stability

“…Besides the peak intensity and position, it was observed that the peak width was broadened in perovskite film after bending or folding, due to that the iodine‐rich segregations and microstrain created by atomic displacement. [ 27,28 ] Additionally, Figure 5d displays the change of steady‐state photoluminescence (PL) of perovskite films subjected to different strains. It can be seen that the larger the strain value, the lower is the PL intensity, indicating the more the nonradiative recombination centers.…”