Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
Publication date: 20th April 2022
The interest in novel photovoltaic materials, especially perovskites, increased rapidly. Within a decade, perovskite solar cells (PSCs) attained a record efficiency of 25,7% by 2022 (UNIST, Korea). Thereby, the development of PSCs draws more and more attention due to their highly efficient and cost-effective energy generation on Earth and now, even for space applications. Properties such as high specific power (power-to-weight ratio), compatibility with lightweight flexible substrates, and high radiation resistance show that PSCs have the potential of being the next generation of space photovoltaics [1].
The goal of PÆROSPACE (Project lead Dr.-Ing. Claudiu Mortan, Prof. Dr. Michael Saliba, Institute for Photovoltaics, University of Stuttgart) is to investigate the performance and stability of a different number of PSC configurations under space conditions. In regard of this project, the Institute for Photovoltaics (ipv) at the University of Stuttgart is researching on ultra-low weight, ultra-high vacuum (UHV) compatible, temperature and radiation stable perovskite devices.
In light of this, ipv solar cells are firstly prepared and tested on a high-altitude stratosphere balloon of the KSat e.V. (small satellite student society at the University of Stuttgart). The BUBBLE balloons are a series of helium-filled balloons for testing KSat-internal projects and external payloads at an altitude of up to 35 km over 90 minutes. The knowledge about the behavior of our solar cells in the stratospheric conditions (e.g. low ambient pressure of 5 mbar and temperatures down to -60°C) is the base for a successful apllication in space [2].
For this purpose, two material compositions of PSCs are developed and mounted on top of the gondola of the balloon. The incoming light from the sun is measured using a spectrometer, and the IV characteristics are recorded by means of a mobile characterization unit with a microcontroller. From this data, the efficiencies of the solar cells can be calculated. To investigate the time resolved stability of the solar cells, visible light spectroscopy using an on-board spectrometer is employed. Moreover, the holder construction for PSCs and electronic measurement equipment is designed.
The aim of the PÆROSPACE project is to answer the following research questions: How efficient and how stable are PSCs in space? Which perovskite material compositions are more suitable for space applications? How do space conditions influence perovskite solar cells?