Proceedings of Materials for Sustainable Development Conference (MAT-SUS) (NFM22)
Publication date: 11th July 2022
Thermoelectric generators (TEGs) represent a very promising source of renewable energy, as they directly convert (waste) heat into electricity. Most current thermoelectric materials have important drawbacks, such as toxicity, scarceness, and peak operating temperatures above 300 ºC. Herein, we report the thermoelectric properties of different crystalline phases of Sn-based perovskite thin films. A novel 2D phase, Cs2SnI4, is obtained through vacuum thermal deposition and easily converted into the black β phase of CsSnI3 (B-β CsSnI3) by annealing. B-β CsSnI3 is a p-type semiconductor with a figure-of-merit (ZT) ranging from 0.021 to 0.033 for temperatures below 100 ºC, which makes it a promising candidate for applications such as the so-called Internet of Things (IoT). The B-β phase is stable under an inert atmosphere but spontaneously oxidizes to Cs2SnI6 when exposed to air in less than two days. In-detail thermoelectric study for both compounds is presented, showing potential for implementation in low-temperature operating TEGs.
The research leading to these results has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 834431). Authors acknowledge support from the Comunitat Valenciana (IDIFEDER/2018/061 and PROMETEU/2020/077), as well as by the Ministry of Science and Innovation (MCIN), and the Spanish State Research Agency (AEI): Project PCI2019-111829-2 funded by MCIN/AEI/10.13039/501100011033 and by the European Union; Project CEX2019-000919-M funded by MCIN/AEI/10.13039/501100011033 Dutch Research Council (NWO, FOM Focus Group “Next Generation Organic Photovoltaics”) P. S. thanks the Spanish Ministry of Universities for her pre-doctoral grant (FPU18/01732 and EST19/00295). F. P. acknowledges funding from the Ramón y Cajal program of the Spanish Ministry of Science (RYC2020-028803-I).