A research paper titled "Micro-homogeneity of lateral energy landscapes governs the performance in perovskite solar cells" was published in Nature Communications by a team led by Professor Xue Jingjing of Zhejiang University. Shi Pengju, a member of the team, is the first author, and Professor Xue Jingjing is the corresponding author.
Key Highlight: Using an organic amidine salt-based passivating agent, they provide a uniform lateral energy landscape at the microscopic level, significantly improving the performance of PSCs and modules. Small-area devices (0.1 cm²) and solar modules (27.2 cm²) achieved world-class PCEs of 25.5% and 22.5%, respectively (certified active area PCE of 23.4%). The PSCs also maintained a high stability of 90% efficiency at 70°C for approximately 6,000 hours.
To reduce unproductive charge recombination and thereby achieve high-efficiency perovskite solar cells, suppressing energy disorder in the vertical direction of photovoltaic devices (charge carriers are forced to move in the vertical direction) has been extensively studied. In contrast, addressing energy disorder in the lateral direction in large-area modules has been largely overlooked. To address this issue, Researcher Xue Jingjing's team employed a two-step method to surface-treat FAPbI3-based perovskite films (FAxCs1-xPbI3) with organic ammonium and amidine passivators, respectively. Their research demonstrated that micro-inhomogeneities in the lateral energetics of formamidinium-based perovskite films significantly impact device performance, particularly regarding device stability and amplification. By using organic amidine salt passivators, rather than the most commonly used organic ammonium passivants, they suppressed micro-inhomogeneities in the lateral energy landscape, significantly improving the device stability and efficiency of FA-based single-junction perovskite solar cells.
Small-area devices and solar modules (27.2 cm2) achieved champion aperture PCEs of 25.5% and 22.5%, respectively (certified active area PCE of 23.4%). The PSCs maintained 90% efficiency for approximately 6,000 hours at 70°C, highlighting the impact of lateral energy landscape micro-uniformity on PSC performance.
Fig. 1 | Micro-inhomogeneity of the lateral energy landscape in perovskite thin films. A Molecular structures of organic ammonium and amidinium passivators. B KPFM images of perovskite films treated with PAm, PAd, PPAm, and PPAd. C FTIR spectra of pure and PbI2-bound PAm, PAd, PPAm, and PPAd. D Crystal structures of PPAd- and PPAm-based low dimensional perovskite phases.
Fig. 2 | Lateral energetic inhomogeneity-induced charge carrier behaviors. A HTPL microscopic images of perovskite films treated with PPAm and PPAd. B Pixel-by-pixel statistical plots of the carrier lifetime extracted from the HTPL images for PPAm and PPAd. FWHM denotes the full-width half maximum (FWHM) of the lifetime distribution. C Line profiles of the carrier lifetime extracted from typical regions of the HTPL maps for PPAm and PPAd. D Surface-carrier kinetics pumped at 2.25, 2.07, 1.91, and 1.65 eV probed by TRS for perovskite films treated with PPAm and PPAd.
Fig. 3 | Film stability and degradation mechanisms. TRPL monitoring of perovskite films with A PPAm and B PPAd. C The evolution of average TRPL lifetime during the aging tests for perovskite films with PPAm and PPAd. D PL peak position maps via in situ PL mapping measurement for perovskite films during an accelerated aging test. E Line profiles of the PL peak position for PPAm and PPAd before and after aging. F Corresponding PL intensity maps for the perovskite films. G Line profiles of the PL intensity before and after aging.
Fig. 4 | Device performance of perovskite solar cells and modules. A J–V curves and B PCE statistics of perovskite solar cell devices fabricated using one-step method with PPAm, PPAd, and the control. C Certified device performance of the perovskite solar module of an aperture area of 27.2 cm2 fabricated with PPAd.D PCE statistics of perovskite solar modules fabricated with PPAm, PPAd, and the control. MPP tracking under continuous one-sun light soaking at ~70 °C of E perovskite solar cell and F perovskite solar modules.
本文来源：DOI: 10.1038/s41467-024-53953-4
https://doi.org/10.1038/s41467-024-53953-4