Controlled Crystallization of the Methylammonium Halide Layer in Thin-Film Perovskite Solar Cells

薄膜钙钛矿太阳能电池中甲基卤化铵层的受控结晶

• 批准号: 322532324
• 负责人: Dr. Christian Weinberger
• 金额: --
• 依托单位: Arbeitskreis Anorganische Funktionsmaterialien
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/322532324?language=en
• 关键词: Controlled; Crystallization; Methylammonium; Halide; Layer

To boost the performance of perovskite solar cells, especially the growth of the crystalline perovskite phase needs to be improved, as stated above. This is the objective of this project proposal.1. Scaffold designTo date most of the porous scaffold layers that are used for the fabrication of structured films for photovoltaic energy conversion are based on interconnected, granular particles, which limits the control of the porosity of the generated film. The size of the inter-particular voids (pores) in particle-based films is generally quite small and exhibits a broad distribution. To increase the pore size it is necessary to use larger particles, which at the same time decreases the efficiency. Therefore, ordered mesoporous scaffolds (synthesized by the sol-gel method or by nanocasting, details are stated in the work plan) bear the advantage of larger pores at constant wall thickness. A larger pore size will allow for larger (yet still confined) perovskite crystals with fewer grain boundaries where charge recombination can occur. Therefore the project aims at a pore size between 5 nm and 100 nm. The advantage of such a nanoporous scaffold lies in the narrow distribution of pore sizes, which is advantageous to particle-based films. 2. Influence of the crystallization and crystallite size of the perovskite-containing layer on the performance of the deviceThe deposition of a uniform perovskite-containing layer is one of the key challenges in the preparation of efficient and reproducible PSCs. A nanoporous scaffold layer (as stated above) facilitates better control of the crystallization process.3. Charge transport and recombination in perovskite solar cellsClarifying the charge transport and recombination in perovskite solar cells is of paramount importance in developing efficient devices, i.e. by tuning the perovskite crystal size (see Objective 2.1) or by developing and implementing novel charge-selective contacts. This adjustment of the energy levels (band structure) of the structured films increases the performance of the perovskite solar cells, aiming to minimize the recombination at the contacts and to extract charges. Therefore, it is necessary to clarify the drift length and charge carrier mobility within the device. These parameters can be determined by charge carrier extraction by linearly increasing voltage (CELIV measurements.

如上所述，为了提高钙钛矿太阳能电池的性能，特别是需要改善结晶钙钛矿相的生长。这是本项目提案的目标。支架设计迄今为止，用于制造用于光伏能量转换的结构化膜的大多数多孔支架层是基于互连的粒状颗粒，这限制了对所产生的膜的孔隙率的控制。颗粒基膜中的颗粒间空隙（孔隙）的尺寸通常相当小，并呈现出广泛的分布。为了增加孔径，必须使用较大的颗粒，这同时降低了效率。因此，有序的中孔支架（通过溶胶-凝胶法或纳米铸造合成，细节在工作计划中说明）具有在恒定壁厚下具有较大孔的优点。更大的孔径将允许更大的（但仍然受限的）钙钛矿晶体，其具有更少的晶界，在晶界处可以发生电荷复合。因此，该项目的目标是孔径在5 nm和100 nm之间。这种纳米多孔支架的优点在于孔径分布窄，这对基于颗粒的膜是有利的。 2.含钙钛矿层的结晶和微晶尺寸对器件性能的影响沉积均匀的含钙钛矿层是制备高效和可重复的PSC的关键挑战之一。纳米多孔支架层（如上所述）有助于更好地控制结晶过程。钙钛矿太阳能电池中的电荷传输和复合澄清钙钛矿太阳能电池中的电荷传输和复合对于开发高效器件至关重要，即通过调整钙钛矿晶体尺寸（参见目标2.1）或通过开发和实施新型电荷选择性接触。结构化膜的能级（能带结构）的这种调整提高了钙钛矿太阳能电池的性能，旨在最小化接触处的复合并提取电荷。因此，有必要阐明器件内的漂移长度和载流子迁移率。这些参数可以通过线性增加电压的电荷载流子提取（CELIV测量）来确定。