Ultralow thermal conductivity in all-inorganic halide perovskites

Abstract

Controlling the flow of thermal energy is crucial to numerous applications ranging from microelectronic devices to energy storage and energy conversion devices. Here, we report ultralow lattice thermal conductivities of solution-synthesized, single-crystalline all-inorganic halide perovskite nanowires composed of CsPbI (0.45 ± 0.05 W·m·K), CsPbBr (0.42 ± 0.04 W·m·K), and CsSnI (0.38 ± 0.04 W·m·K). We attribute this ultralow thermal conductivity to the cluster rattling mechanism, wherein strong optical-acoustic phonon scatterings are driven by a mixture of 0D/1D/2D collective motions. Remarkably, CsSnI possesses a rare combination of ultralow thermal conductivity, high electrical conductivity (282 S·cm), and high hole mobility (394 cm·V·s). The unique thermal transport properties in all-inorganic halide perovskites hold promise for diverse applications such as phononic and thermoelectric devices. Furthermore, the insights obtained from this work suggest an opportunity to discover low thermal conductivity materials among unexplored inorganic crystals beyond caged and layered structures.

Revisit to the Impacts of Rattlers on Thermal Conductivity of Clathrates

“…A novel guideline concept, phonon-glass and electron-crystal, is proposed to optimize thermoelectric performance (Slack and Rowe, 1995;Beekman et al, 2015). The previous studies have demonstrated that host-guest systems are ideal platform for this concept, such as clathrates (Takabatake et al, 2014), perovskites (Lee et al, 2017), and skutterudites (Ren et al, 2017), in which the lattice thermal conductivity (κ l ) can be dramatically reduced to a glass-like value while maintaining excellent electric properties. Because of their desirable thermoelectric behaviors, host-guest systems are identified as one of the most promising materials in practical thermoelectric applications.…”

Low‐dimensional metal halide perovskites and related optoelectronic applications

“…With the reduced dimensions, some inherent natures like band structure and photon transport will behave differently. For example, reduced thermal conductance from the enhanced boundary scattering, together with the improved Seebeck coefficient from the modified energy band, makes low‐dimensional perovskites potential materials for thermoelectrics . Recently, Wang et al have investigated the cation dynamics governed by thermal properties in different types of perovskite nanowires .…”

Light Generation in Lead Halide Perovskite Nanocrystals: LEDs, Color Converters, Lasers, and Other Applications

“…e) Thermal conductivity of MAPbX 3 as a function of temperature. Reproduced with permission . Copyright 2018, American Chemical Society.…”

“…f) Temperature dependence of thermal expansion d L / L 0 of MAPbX 3 . Reproduced with permission . Copyright 2018, American Chemical Society.…”

“…Superior electrical conductivity combined with ultralow thermal conductivity could make LHP‐NCs a potential candidate for thermoelectric applications (Figure e,f); however, the mechanical stress from the structural instability of polymorphism limits the operational stability of LHP‐NC applications, especially for electrically driven devices of LEDs and prospective lasers because of the high amount of heating generated by a high driving current density . For a complete device, high‐quality device encapsulation is essential to protect LHP‐NCs and other functional layers against oxygen and moisture in the ambient atmosphere.…”