Damp heat–stable perovskite solar cells with tailored-dimensionality 2D/3D heterojunctionsIf perovskite solar cells (PSCs) with high power conversion efficiencies (PCEs) are to be commercialized, they must achieve long-term stability, which is usually assessed with accelerated degradation tests. One of the persistent obstacles for PSCs has been successfully passing the damp-heat test (85°C and 85% relative humidity), which is the standard for verifying the stability of commercial photovoltaic (PV) modules. We fabricated damp heat-stable PSCs by tailoring the dimensional fragments of two-dimensional perovskite layers formed at room temperature with oleylammonium iodide molecules; these layers passivate the perovskite surface at the electron-selective contact. The resulting inverted PSCs deliver a 24.3% PCE and retain >95% of their initial value after >1000 hours at damp-heat test conditions, thereby meeting one of the critical industrial stability standards for PV modules.
Efficient and stable perovskite-silicon tandem solar cells through contact displacement by MgF <i> <sub>x</sub> </i>The performance of perovskite solar cells with inverted polarity (p-i-n) is still limited by recombination at their electron extraction interface, which also lowers the power conversion efficiency (PCE) of p-i-n perovskite-silicon tandem solar cells. A MgF x interlayer with thickness of ~1 nanometer at the perovskite/C 60 interface favorably adjusts the surface energy of the perovskite layer through thermal evaporation, which facilitates efficient electron extraction and displaces C 60 from the perovskite surface to mitigate nonradiative recombination. These effects enable a champion open-circuit voltage of 1.92 volts, an improved fill factor of 80.7%, and an independently certified stabilized PCE of 29.3% for a monolithic perovskite-silicon tandem solar cell ~1 square centimeter in area. The tandem retained ~95% of its initial performance after damp-heat testing (85°C at 85% relative humidity) for >1000 hours.
28.2%-efficient, outdoor-stable perovskite/silicon tandem solar cellHigh-Performance Perovskite Single-Junction and Textured Perovskite/Silicon Tandem Solar Cells via Slot-Die-CoatingIn this work, we report perovskite solar cells in the planar p–i–n configuration based on single-step, anti-solvent-free, low-temperature (70 °C) slot-die-coated methylammonium lead tri-iodide (MAPbI3). The devices are fabricated on hydrophobic poly(triarylamine) (PTAA) surfaces, using key strategies such as solvent engineering, enhanced ink–substrate dynamics, and surface passivation, enabling a power conversion efficiency (PCE) of 21.8%. We also adapted the technique to achieve the first slot-die-coated perovskite/silicon monolithic 2-terminal tandems, achieving a PCE of 23.8% utilizing a textured silicon bottom cell.
Light-induced activation of boron doping in hydrogenated amorphous silicon for over 25% efficiency silicon solar cellsAbstract Recent achievements in amorphous/crystalline silicon heterojunction (SHJ) solar cells and perovskite/SHJ tandem solar cells place hydrogenated amorphous silicon (a-Si:H) at the forefront of photovoltaics. Due to the extremely low effective doping efficiency of trivalent boron in amorphous tetravalent silicon, light harvesting of aforementioned devices is limited by their fill factors (FFs), a direct metric of the charge carrier transport. It is challenging but crucial to develop highly conductive doped a-Si:H with minimal FF losses. Here we report that light soaking can efficiently boost the dark conductance of boron-doped a-Si:H thin films. Light induces diffusion and hopping of weakly bound hydrogen atoms, which activates boron doping. The effect is reversible and the dark conductivity decreases over time when the solar cell is no longer illuminated. By implementing this effect to SHJ solar cells, we achieved a certified total-area power conversion efficiency of 25.18% with a FF of 85.42% on a 244.63 cm 2 wafer.