溶液压合静扩散方法制备高效稳定的钙钛矿太阳能电池

The external factors such as moisture, oxygen, temperature, UV light, etc. result in an obvious reduced efficiency of perovskite solar cells (PSCs). Thus, it’s imminent to find a solution to improve the stability of PSCs. The subsequent encapsulation of the fabricated devices is extremely necessary for stable PSCs. In this work, we propose a solution-processed press-diffusion method to simultaneously fabricate and encapsulate PSCs devices. The devices are fabricated by pressing two perovskite films on different substrates, which effectively prevent water and oxygen. For the diffusion property between perovskites upon heating process, the morphologies with perfect crystals and less pin-hole can be formed. This method can achieve the whole device solution-processed preparation, which reduces the preparation cost from evaporating electrode under high vacuum and contributes to large-scale processing. The morphology and crystallinity of the perovskite layers from one-step or two-step methods need to be studied. Introduction of solvent or additives may increase the interfacial contact, which is in favor of effectively transporting charges. Double heterojunction perovskite solar cells with appropriate band gaps, carrier diffusion length and carrier separation efficiency can be fabricated by choosing different halogen anions and cations. Moreover, by pressing the buffer layers from the front and back perovskite cells, the highly efficient and stable tandem PSCs can been prepared to further capture more solar light.

水氧、温度、紫外光照等外界条件会导致钙钛矿电池效率衰减严重，因此寻找一种解决钙钛矿太阳能电池器件稳定性的方案迫在眉睫。本项目拟采用溶液压合静扩散的方法同时实现钙钛矿太阳能电池的制备和封装工艺，通过两块基底之间的压合及加热控制上下两层钙钛矿材料之间的扩散融合，从而形成晶粒完善且无孔洞的钙钛矿层，有效地阻挡外界的水氧达到封装效果。此方法能够实现整个器件全溶液加工制备，降低了高真空蒸镀电极产生的制备成本。研究一步法和两步法钙钛矿压合过程中形貌和结晶性变化，通过溶剂或者添加物的引入提高界面接触，实现钙钛矿层之间电荷的有效传输。研究压合不同卤素/阳离子的钙钛矿层形成的双层异质结钙钛矿太阳能电池中垂直分布的钙钛矿的带隙、载流子扩散长度和载流子分离效率。分别制备钙钛矿前电池和后电池，通过压合缓冲层，改善钙钛矿对太阳光的捕获能力，获得高效稳定的钙钛矿串联电池。

该项目已在Adv. Mater. (IF=27.398), Adv. Energy Mater. (IF=25.245), Adv. Funct. Mater. (IF=16.836), Adv. Sci. (IF=15.840), ACS Appl. Mater. Interfaces (IF=8.758), Chem. Commun. (IF=5.996) 等期刊发表SCI论文15篇，其中封面论文3篇，影响因子10.0以上7篇。编著《钙钛矿太阳电池》专著1部。获授权发明专利7项。获2020年度江西省自然科学奖二等奖（排名第一，已公示）、2019年度教育部自然科学二等奖（排名第三）。本项目采用溶液压合静扩散的方法同时实现钙钛矿太阳能电池的制备和封装工艺。通过两块基底之间的压合及加热控制上下两层钙钛矿材料之间的扩散融合，从而形成晶粒完善且无孔洞的钙钛矿层，有效地阻挡外界的水氧达到封装效果。此方法能够实现整个器件全溶液加工制备，降低了高真空蒸镀电极产生的制备成本。项目研究了钙钛矿压合过程中形貌和结晶性变化，通过溶剂处理提高界面接触，实现钙钛矿层之间电荷的有效传输（Org. Electron. 2017）。研究了柔性自封装工艺成功制备了超柔性结构钙钛矿太阳电池，使其具有出色的压皱耐受性和水浸泡性（Chem. Commun. 2021, in revision）。研究了自粘性聚乙烯-醋酸乙烯酯（EVA）胶反溶剂处理钝化钙钛矿缺陷，并改善钙钛矿与电子传输层之间结合力，提高器件阻水性和机械弯折性（Adv. Funct. Mater. 2019a）。另外，还针对钙钛矿太阳电池界面缺陷修复和增韧开展了系列研究，实现了整个钙钛矿太阳电池器件具有优异的弯折稳定性（Adv. Mater. 2020, Adv. Energy. Mater. 2019, Adv. Funct. Mater. 2019b/2017, Adv. Sci. 2019/2018, Chem. Commun. 2020/2019）。