Optoelectronic properties of hybrid metal halide perovskites: from nanoscale to devices

杂化金属卤化物钙钛矿的光电特性：从纳米级到器件

基本信息

批准号：
EP/V001302/1
负责人：
Rebecca Milot
金额：
$ 48.79万
依托单位：
University of Warwick
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2021
资助国家：
英国
起止时间：
2021 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FV001302%2F1
关键词：
Optoelectronic properties hybrid metal halide

项目摘要

Anthropogenic climate change is currently one of the biggest challenges facing our society. In order to mitigate the detrimental effects of burning fossil fuels and releasing CO2 into the atmosphere, we must switch to clean, renewable sources as quickly as possible. Solar energy is one of the most promising options available because it has the potential to completely meet our entire global energy requirements. Although the solar energy industry has seen rapid development in recent years, challenges still remain to increase the efficiency of photovoltaic devices while decreasing or maintaining costs. Hybrid metal halide perovskite thin films are promising materials for achieving these goals as high efficiency devices which rival existing technology can be easily synthesized via solution processing methods using inexpensive, earth-abundant materials. However, current state-of-the-art perovskite materials struggle to maintain long-term stability under ambient conditions. Two-dimensional, Ruddlesden-Popper phase perovskites have demonstrated superior stability, and have thus attracted much attention in the perovskite community, although photovoltaic devices made with these materials have not been able to achieve the same high efficiencies as their 3D counterparts. As it is currently unknown whether this inefficiency is due to intrinsic limitations of the material or to extrinsic factors fixable with improved processing procedures, a comprehensive study of the fundamental optoelectronic properties in these materials is desperately needed. This research will fill this knowledge gap by fully characterizing the optoelectronic properties of 2D perovskites in order to determine their ultimate viability for use in solar cells. This task is far from straightforward, however, as many competing factors can limit efficient charge transport in these materials. In addition to exhibiting high exciton binding energies, 2D perovskites also demonstrate increased doping density and decreased crystallinity associated with their thin-film microstructure, all of which previous work has shown to limit charge-carrier diffusion lengths (Milot et al, Nano Lett, 2016). The challenge for understanding the optoelectronic properties in these materials is being able to isolate the effects of the intrinsic properties (e.g excitonic effects) from extrinsic properties such as doping density and crystallinity which could be altered with improved processing methods. As many of the extrinsic properties can further change with incorporation into solar cells, this problem is nontrivial. To address this issue, this research will pioneer a new approach by studying optoelectronic properties from single crystals to devices in order to gain a full picture of intrinsic properties and determine how they are affected by extrinsic factors including microstructure and solar cell inclusion. To best enable comparisons, it will utilize THz and photoluminescence (PL) spectroscopy, two of the most versatile techniques for the analysis of optoelectronic properties including charge-carrier mobility and recombination dynamics. It will further harness the versatility of these two techniques by combining THz scattering near-field optical microscopy (THz-SNOM) and time-resolved PL microscopy analyses for the first time, adding the capability of nanoscale spatial resolution to the existing capabilities for ultrafast time resolution. Through comparison with conventional measurements of photovoltaic power conversion efficiencies, it will identify pathways to improvement in device fabrication. The greater understanding of the optoelectronic properties of 2D perovskites that this research presents will lead directly to the development of high efficiency solar cells to meet our energy needs.

人为气候变化目前是我们社会面临的最大挑战之一。为了减轻燃烧化石燃料并将二氧化碳释放到大气中的有害影响，我们必须尽快切换到清洁，可再生的来源。太阳能是可用的最有希望的选择之一，因为它有可能完全满足我们的整个全球能源需求。尽管近年来太阳能行业已经发展了迅速的发展，但在降低或维持成本的同时，仍在提高光伏设备效率的挑战仍然存在。杂交金属卤化物钙钛矿薄膜是实现这些目标的有希望的材料，因为高效设备可以使用廉价的，含有的含量的材料来通过溶液加工方法来轻松合成现有技术。但是，当前的最新钙钛矿材料难以在环境条件下保持长期稳定性。二维ruddlesden-popper期钙钛矿表现出了卓越的稳定性，因此在钙钛矿群落中引起了很多关注，尽管用这些材料制造的光伏设备无法达到与3D对应物相同的高效率。由于目前尚不清楚这种低效率是由于材料的固有局限性还是通过改进的处理程序来固定的外部因素，因此迫切需要对这些材料中基本光电特性的全面研究。这项研究将通过充分表征2D Perovskites的光电特性来填补这一知识空白，以确定其在太阳能电池中使用的最终生存能力。但是，这项任务远非直接，因为许多竞争因素可以限制这些材料中有效的电荷运输。除了表现出较高的激子结合能外，2D钙钛矿还表明，与其薄膜微观结构相关的掺杂密度和降低的结晶度，所有这些先前的工作都显示出限制了电荷载流子扩散长度（Milot等，Nano Lett，2016年）。理解这些材料中光电特性的挑战是能够将固有性能（例如兴奋性效应）的影响与外在特性（例如掺杂密度和结晶度）隔离，从而通过改进的处理方法改变了掺杂密度和结晶度。由于许多外部特性可以随着掺入太阳能电池的融合而进一步改变，因此这个问题是不平凡的。为了解决这一问题，这项研究将通过研究从单晶到设备的光电特性来开创一种新方法，以便获得固有特性的全部图景，并确定它们如何受到外在因素的影响，包括微结构和太阳能细胞包含。为了最好地启用比较，它将利用THZ和光致发光（PL）光谱，这是两种用途最广泛的技术，用于分析光电特性，包括电荷载体迁移率和重组动力学。它将通过首次将THZ散射近场光学显微镜（THZ-SNOM）和时间分辨PL显微镜分析组合来进一步利用这两种技术的多功能性，从而增加了纳米级空间分辨率的能力，从而为超快时间分辨率的现有功能提供了能力。通过与光伏电源转换效率的常规测量进行比较，它将确定改进设备制造的途径。对本研究提出的2D钙钛矿的光电特性的更大了解将直接导致高效太阳能电池的发展，以满足我们的能源需求。

项目成果

期刊论文数量（6）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Efficient Terahertz Generation via Optical Rectification in Halide Perovskites

DOI：
10.1109/irmmw-thz57677.2023.10299221
发表时间：
2023-09
期刊：
2023 48th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)
影响因子：
0
作者：
Nathaniel P Gallop;D. Sirbu;David Walker;Pablo Docampo;J. Lloyd-Hughes;R. Milot
通讯作者：
Nathaniel P Gallop;D. Sirbu;David Walker;Pablo Docampo;J. Lloyd-Hughes;R. Milot

Charge-Carrier Dynamics in Mixed Lead-Tin 2D/3D Metal Halide Perovskites

混合铅锡 2D/3D 金属卤化物钙钛矿中的载流子动力学