RESUMO
Perovskite solar cells (PSCs) are among the most promising photovoltaic technologies owing to their exceptional optoelectronic properties1,2. However, the lower efficiency, poor stability and reproducibility issues of large-area PSCs compared with laboratory-scale PSCs are notable drawbacks that hinder their commercialization3. Here we report a synergistic dopant-additive combination strategy using methylammonium chloride (MACl) as the dopant and a Lewis-basic ionic-liquid additive, 1,3-bis(cyanomethyl)imidazolium chloride ([Bcmim]Cl). This strategy effectively inhibits the degradation of the perovskite precursor solution (PPS), suppresses the aggregation of MACl and results in phase-homogeneous and stable perovskite films with high crystallinity and fewer defects. This approach enabled the fabrication of perovskite solar modules (PSMs) that achieved a certified efficiency of 23.30% and ultimately stabilized at 22.97% over a 27.22-cm2 aperture area, marking the highest certified PSM performance. Furthermore, the PSMs showed long-term operational stability, maintaining 94.66% of the initial efficiency after 1,000 h under continuous one-sun illumination at room temperature. The interaction between [Bcmim]Cl and MACl was extensively studied to unravel the mechanism leading to an enhancement of device properties. Our approach holds substantial promise for bridging the benchtop-to-rooftop gap and advancing the production and commercialization of large-area perovskite photovoltaics.
RESUMO
Besides further improvement in the power conversion efficiency (PCE) of perovskite solar cells (PSC), their long-term stability must also be ensured. Additives such as organic cations with halide counter anions are considered promising candidates to address this challenge, conferring both higher performance and increased stability to perovskite-based devices. Here, a stabilizing additive (N,N-dimethylmethyleneiminium chloride, [Dmmim]Cl) is identified, and its effect on charge carrier mobility and lifetime under thermal stress in triple cation perovskite (Cs0.05 MA0.05 FA0.90 PbI3 ) thin films is investigated. To explore the fundamental mechanisms limiting charge carrier mobility, temperature-dependent microwave conductivity measurements are performed. Different mobility behaviors across two temperature regions are revealed, following the power law Tm , indicating two different dominant scattering mechanisms. The low-temperature region is assigned to charge carrier scattering with polar optical phonons, while a strong decrease in mobility at high temperatures is due to dynamic disorder. The results obtained rationalize the improved stability of the [Dmmim]Cl-doped films and devices compared to the undoped reference samples, by limiting temperature-activated mobile ions and retarding degradation of the perovskite film.
RESUMO
Despite the remarkable progress in power conversion efficiency of perovskite solar cells, going from individual small-size devices into large-area modules while preserving their commercial competitiveness compared with other thin-film solar cells remains a challenge. Major obstacles include reduction of both the resistive losses and intrinsic defects in the electron transport layers and the reliable fabrication of high-quality large-area perovskite films. Here we report a facile solvothermal method to synthesize single-crystalline TiO2 rhombohedral nanoparticles with exposed (001) facets. Owing to their low lattice mismatch and high affinity with the perovskite absorber, their high electron mobility and their lower density of defects, single-crystalline TiO2 nanoparticle-based small-size devices achieve an efficiency of 24.05% and a fill factor of 84.7%. The devices maintain about 90% of their initial performance after continuous operation for 1,400 h. We have fabricated large-area modules and obtained a certified efficiency of 22.72% with an active area of nearly 24 cm2, which represents the highest-efficiency modules with the lowest loss in efficiency when scaling up.