Thermal transport in metal-halide perovskite semiconductors under operating conditions

金属卤化物钙钛矿材料由于其优异的光电性能，在广泛的应用中变得越来越重要。除了太阳能电池（PSC），这一系列材料在发光二极管和激光器的未来应用中也有很大的希望。在广泛的器件应用中，热管理变得越来越重要，因为寿命和性能都受到温度或温度梯度的影响。因此，有机-无机金属卤化物钙钛矿半导体的热输运分析是必不可少的。本项目的核心是金属卤化物钙钛矿半导体在工作条件下的基本热输运分析。更具体地说，我们将专注于全无机金属卤化物钙钛矿（CsPbX 3，X = Br和Cl），这是有前途的发光器件，并提供令人鼓舞的热稳定性。我们的研究旨在全面了解这些材料的热传输及其对操作设备的影响。因此，通过扫描近场热显微镜进行热研究（热导率、热扩散率和体积热容）将通过X射线衍射、拉曼光谱、电子背散射衍射、电学表征和（时间分辨的）光致发光光谱，以获得材料性质，例如结晶度和晶体取向、载流子密度、迁移率、介电性质，扩散长度和复合率，在这些半导体中。研究将在薄膜上进行，温度和薄膜厚度的依赖性，这可能会对热，晶体和电荷传输特性产生重大影响。在这方面，将评估Cs铅卤化物的0 D-、2D-和3D-多晶型物。将明确研究的热性能相对于主动操作的金属卤化物钙钛矿设备依赖于电荷载流子/激子浓度。钙钛矿结构由于温度和施加的电场而降解所导致的热性能变化将得到确认。将评估从金属卤化物钙钛矿到相邻功能层的热传输。该项目的主要目标是开发一个框架，该框架允许用热描述补充通常考虑的金属卤化物钙钛矿器件的电光描述，这将允许预测活性钙钛矿层和相邻材料界面内的基本传热特性。我们预计，该项目中设想的结果将对优化金属-陶瓷材料中的热管理至关重要。卤化物钙钛矿器件，如LED和激光器。此外，我们预计其他应用，如热电设备，也将受益于该项目产生的见解。

Metal-halide perovskites are becoming more and more important in a wide range of applications due to their outstanding (opto-)electronic properties. Aside solar cells (PSCs), this family of materials also holds great promise for future applications in light emitting diodes and lasers. In a wide range of device applications, thermal management becomes increasingly important, because both lifetime and performance are influenced by temperature or temperature gradients. Thus, the analysis of thermal transport in organic–inorganic metal-halide perovskites is indispensable.Fundamental heat transport analysis of metal-halide perovskite semiconductors under operating conditions are in the core of this project. More specifically, we will focus on all-inorganic metal-halide perovskites (CsPbX3, X = Br and Cl), which are promising for light emitting devices and provide encouraging thermal stability. Our research is aimed to provide a comprehensive understanding of the thermal transport in these materials and its implications for operating devices. Hereby, thermal investigations by Scanning Near-field Thermal Microscopy (thermal conductivities, thermal diffusivities, and volumetric heat capacities) will be complemented by X-ray diffraction, Raman spectroscopy, electron backscatter diffraction, electrical characterization, and (time resolved) photoluminescence spectroscopy to get access to material properties, such as crystallinity and crystal orientation, carrier densities, mobilities, dielectric properties, diffusion lengths, and recombination rates, in these semiconductors.The studies will be carried out on thin films in dependence on temperature and film thicknesses, which can have a significant impact on the thermal, crystal, and charge transport properties. The 0D-, 2D-, and 3D-polymorphs of Cs lead halides will be evaluated in this regard. The thermal properties will be explicitly studied with respect to actively operated metal-halide perovskite devices in dependence on charge carrier/exciton concentrations. Changes in thermal properties resulting from degradation of perovskite structures due to temperature and applied electric fields will be recognized. The heat transport from metal-halide perovskites to adjacent functional layers, will be evaluated. The main goal of the project is to develop a framework that allows to complement the typically considered electro-optical description of metal-halide perovskite devices with thermal description, which would allow to predict fundamental heat transfer properties within the active perovskite layers and the interfaces to adjacent materials.We expect that the results envisaged in this project will be essential to optimize the thermal management in metal-halide perovskite devices, such as LEDs and lasers. Moreover, we foresee that other applications, such as thermoelectric devices, would likewise benefit from the insights generated in this project.