【作者】 李慧；

【导师】 马林政； 李云飞；

【作者基本信息】 山东科技大学 ， 材料与化工（专业学位）， 2025， 硕士

【摘要】 太阳能作为一种取之不尽、用之不竭的清洁能源,其高效利用和转化技术已经成为全球科研领域的热点话题。特别是钙钛矿太阳能电池（Perovskite Solar Cells,简称PSC）的出现,宛如一颗冉冉升起的新星,为光伏产业注入了新的活力和希望,预示着未来能源技术的无限可能。通常,具有较高的光电转化效率的钙钛矿太阳能电池依赖于添加有机成分,这不仅导致制备成本的提高也导致器件的稳定性下降。而使用铯离子全取代有机阳离子的全无机钙钛矿材料CsPbI₂Br钙钛矿太阳能电池因其卓越的热稳定性和优异的光电性能和较低的制备成本而受到广泛关注。近年来,研究者们不断优化CsPbI₂Br太阳能电池的制备技术,在提高其光电转换效率和稳定性方面取得了显著进展。然而,由于溶液法制备的薄膜由于快速结晶,薄膜体相与界面处存在大量缺陷,质量欠佳。在无机钙钛矿薄膜中,缺陷的存在对钙钛矿太阳能电池（PSCs）的光电转换效率和长期稳定性构成了显著挑战,而且还作为电子掺杂剂影响着界面能量学和电荷转移动力学,导致载流子复合增加,从而降低电池的性能。特别是在空气中制备钙钛矿太阳能电池时,水分和氧气的存在对钙钛矿的结晶过程极为不利,它们会破坏钙钛矿的相稳定性,导致其出现大量蓬松的软晶格缺陷与纳米杂质,这些缺陷和杂质主要集中在钙钛矿材料的表面,而光的吸收和电荷的传输主要发生在这一区域。因此,水分和氧气的存在不仅影响了钙钛矿薄膜的质量降低器件的性能,还可能成为降解的起始点,严重影响CsPbI₂Br太阳能电池在空气中的稳定性,已成为其商业化进程的主要障碍。在此,本论文针对CsPbI₂Br钙钛矿薄膜体相与表面处存在大量缺陷这一核心科学问题,系统开展了多方面的研究,具体工作如下:（1）绿色生物小分子掺杂优化了CsPbI₂Br钙钛矿薄膜的结晶和电荷传输过程。本研究在钙钛矿前驱体中加入了天然添加剂,以改善无机CsPbI₂Br薄膜的质量,通过钝化分子与钙钛矿中欠配位的Pb²⁺之间的强相互作用,钝化缺陷,在无机CsPbI₂Br钙钛矿表面形成有效的少n型掺杂,同时在钙钛矿/碳界面顶部形成n/n-结,加速碳基PSC中的电荷提取并抑制载流子非辐射复合。最终,不仅减少了迟滞,器件效率高达15.0%,并且稳定性显著提高,空气中的储存期提高至65天（94.74%的效率保留率）,在N₂中持续光照射230 h以上效率保留率达到82%。绿色生物小分子掺杂的成功应用,不仅优化了薄膜的结晶质量和电荷传输过程,还显著提高了器件的效率和稳定性,为钙钛矿太阳能电池的商业应用提供了有力支持。（2）空气中溶剂处理实现钙钛矿膜晶格蚀刻-重建制备高效全无机CsPbI₂Br太阳能电池。本研究提出了一种策略,通过在高温下将空气中制造的钙钛矿膜浸泡在低极性有机酯中,刻蚀去除表面缺陷层的同时,触发表面晶格动态分解和原位重建过程。通过分子动力学模拟和实验结果表明,全无机CsPbI₂Br钙钛矿由于在极性溶剂中的弱溶解度和高温诱导退火过程的平衡,首先溶解,然后在固液界面处再结晶为富Br相,使软表面硬化,释放晶格拉应力,有利于减少界面复合,提高结构稳定性。因此,本研究通过创新全无机钙钛矿薄膜的制备策略和技术手段,有效解决了全无机CsPbI₂Br钙钛矿太阳能电池薄膜中的缺陷问题,显著提升了其光电转换效率和稳定性。全空气中制备的碳基CsPbI₂Br器件,获得了15.37%的效率,并具有出色的稳定性。该方法通过空气中弱极性溶剂刻蚀并在加热下触发重结晶的策略,实现了钙钛矿膜晶格的蚀刻与重建,为克服加工条件的限制、实现高效全无机CsPbI₂Br太阳能电池的工业化制备开辟了新的途径,为未来高效且稳定的钙钛矿太阳能电池的大规模生产与应用奠定了坚实的基础,展现了巨大的潜力和可能性。更多还原

【Abstract】 In the critical period when the global ecological environment faces significant challenges and the energy structure urgently needs transformation,the rise of clean energy is seen as key to addressing traditional energy issues.The search for sustainable and clean energy alternatives has become an urgent necessity,with no time to waste.Solar energy,as an inexhaustible and abundant clean resource,has seen its efficient utilization and conversion technologies become a hot topic in global scientific research.In particular,the emergence of perovskite solar cells（Perovskite Solar Cells,abbreviated as PSC）is like a rising star,infusing new vitality and hope into the photovoltaic industry,heralding the boundless possibilities of future energy technologies.Typically,perovskite solar cells with high photovoltaic conversion efficiency rely on the addition of organic components,which not only increases the manufacturing cost but also reduces the stability of the device.In contrast,all-inorganic perovskite materials using cesium ions to fully replace organic cations,known as CsPbI₂Br perovskite solar cells,have gained significant attention due to their excellent thermal stability,superior photovoltaic performance,and lower manufacturing costs.In recent years,researchers have continuously optimized the preparation techniques for CsPbI₂Br solar cells,achieving notable progress in improving their photovoltaic conversion efficiency and stability.However,thin films prepared by solution methods exhibit rapid crystallization,leading to numerous defects at both the bulk and interface regions,resulting in poor quality.In inorganic perovskite thin films,the presence of defects poses a significant challenge to the photovoltaic conversion efficiency and long-term stability of perovskite solar cells（PSCs）.These defects also affect interfacial energetics and charge transfer kinetics as electron dopants,increasing carrier recombination and thus degrading cell performance.Particularly when preparing perovskite solar cells in air,the presence of water and oxygen is highly detrimental to the crystallization process of perovskite,disrupting its phase stability and causing extensive fluffy soft lattice defects and nanoscale impurities.These defects and impurities are primarily concentrated on the surface of the perovskite material,where light absorption and charge transport mainly occur.Therefore,the presence of water and oxygen not only affects the quality of perovskite films and degrades the performance of devices,but also may become the starting point of degradation,seriously affecting the stability of CsPbI₂Br solar cells in air,which has become a major obstacle to its commercialization process.In this paper,we systematically study the core scientific problem of a large number of defects in the bulk and surface of CsPbI₂Br perovskite films.The specific work is as follows:（1）Green bio-molecular doping optimizes the crystallization and charge transport processes of CsPbI₂Br perovskite films.We added natural additives to the perovskite precursors to improve the quality of inorganic CsPbI₂Br films.By passivating the strong interaction between the molecules and the poorly coordinated Pb²⁺in the perovskite,defects are passivated,forming effective n-type doping on the surface of inorganic CsPbI₂Br perovskite.At the same time,an n/n junction is formed at the top of the perovskite/carbon interface,accelerating charge extraction in carbon-based PSCs and suppressing non-radiative carrier recombination.Ultimately,this not only reduces hysteresis but also achieves a device efficiency of up to 15.0%,with significantly improved stability.The storage period in air is extended to 65 days（with an efficiency retention rate of 94.74%）,and the efficiency retention rate remains at 82%after continuous light exposure for over 230 h in N₂.The successful application of green bio-small molecule doping not only optimizes the crystallization quality and charge transport process of the film,but also significantly improves the efficiency and stability of the device,providing strong support for the commercial application of perovskite solar cells.（2）Efficient all-inorganic CsPbI₂Br solar cells are prepared through the lattice etching and reconstruction of perovskite films using air-solvent treatment.We propose a strategy to etch and remove surface defect layers by immersing air-grown perovskite films in low-polarity organic esters at high temperatures,simultaneously triggering dynamic lattice decomposition and in-situ reconstruction on the surface.Molecular dynamics simulations and experimental results show that all-inorganic CsPbI₂Br perovskites first dissolve due to their weak solubility in polar solvents and the equilibrium of high-temperature induced annealing processes,then recrystallize into Br-rich phases at the solid-liquid interface,hardening the soft surface and releasing lattice tensile stress,which helps reduce interfacial recombination and enhances structural stability.Therefore,through innovative preparation strategies and technical means for all-inorganic perovskite films,we effectively address the defect issues in all-inorganic CsPbI₂Br perovskite solar cell films,significantly improving their photovoltaic conversion efficiency and stability.Carbon-based CsPbI₂Br devices prepared in air achieve an efficiency of 15.37%and exhibit excellent stability.This method achieves the etching and reconstruction of perovskite film lattices through the strategy of etching with weakly polar solvents in air and triggering recrystallization under heating.It paves a new way to overcome processing limitations and achieve industrial-scale preparation of efficient all-inorganic CsPbI₂Br solar cells,laying a solid foundation for the large-scale production and application of high-efficiency and stable perovskite solar cells in the future,demonstrating great potential and possibilities.更多还原