Thermal conductivity and diffusivity of triple-cation perovskite halide materials for solar cells

Zhelu Hu , Lionel Aigouy , Zhuoying Chen (1) , Danièle Fournier (2)

1 LPEM - Laboratoire de Physique et d'Etude des Matériaux (UMR 8213)
2 INSP - Institut des Nanosciences de Paris

We report on the measurement of the thermal conductivity and the thermal diffusivity by the technique of modulated thermoreflectance microscopy on a mixed-cation perovskite material [Cs 0.05 (formamidinium 0.83 methylammonium 0.17) 0.95 Pb(I 0.83 Br 0.17) 3 ] widely applied for solutionprocessed perovskite solar cells. Such materials are supposed to present an improved thermal stability compared to methylammonium-based single cation perovskites. Our measurements are performed on perovskite/TiO 2 /SnO 2 :F/SiO 2 structures, with perovskite thicknesses ranging between 250 nm and 1000 nm. This configuration is the one of a real solar cell, with the same substrate and intermediate layers than an operating device. We measured a thermal conductivity k per of 0.26  0.03 W m-1 K-1 and a thermal diffusivity D per of 3.5×10-7  0.5 m 2 s-1. The value for the thermal conductivity is comparable to the one measured on single cation perovskites which is generally in the 0.2-0.6 range. The value for the thermal diffusivity was not reported previously.

Domaines: Sciences de l'ingénieur [physics]; Physique [physics]

Zhelu Hu, Lionel Aigouy, Zhuoying Chen, Danièle Fournier. Thermal conductivity and diffusivity of triple-cation perovskite halide materials for solar cells. Journal of Applied Physics, 2020, 127 (12), pp.125113. ⟨10.1063/1.5138480⟩. ⟨hal-02989866⟩