Thermal Transport in Engineered Hybrid Organic–Inorganic Perovskite Metasurfaces

Abstract

Halide perovskites have recently gained widespread attention for their exceptional optoelectronic properties, which have been illuminated by extensive spectroscopic investigations. In this study, nanophotonic surface engineering using a newly developed soft lithographic technique has been used to reproduce nanostructures with enhanced optical functionalities. The thermal sensitivity of the metasurfaces is first observed in the temperature-dependent photoluminescence (PL) spectra. In order to observe the local changes in heat transport induced by nanopatterning of the perovskite thin films, a noninvasive optical technique based on Raman spectroscopy is employed. The thermophysical properties of the engineered perovskite surfaces are extracted from the softening of the representative peak positions in the Raman spectra, which act as temperature markers. The investigation suggests a comparatively higher rise in the local temperature for the patterned thin films as compared to the pristine thin films. We characterize different imprint geometries on perovskite thin films in terms of both optical and thermal transport simultaneously and report for the first time the existence of a window of thermal tolerance for the metasurfaces within which optical efficiencies can still be maximized.

Chemical Vapor Deposition Growth of Highly Stable Cs2AgBiBr6 Double Perovskite Thin Films and Their Ultralow Thermal Conductivity and Fast Photoresponse

“…In the radial heat wave example, the thermal conductivity can be expressed as K = α ( 1 2 πd ) true( dω normald P true) − 1 where dω is the shift in the Raman peak position of the A 1g mode concerning the change in incident laser power d P on the material surface, α is the first-order temperature coefficient, and d is the thickness of the material. Shen et al and many other researchers demonstrated that the thermal conductivity of perovskite materials is independent of the thickness ( d ) in the range of 90 to 400 nm. , As a result, the influence of thickness “ d ” on thermal conductivity ( K ) may be considered to be insignificant. Thus, the only quantities to examine are α and (dω/d P ).…”

“…Shen et al and many other researchers demonstrated that the thermal conductivity of perovskite materials is independent of the thickness (d) in the range of 90 to 400 nm. 61,62 As a result, the influence of thickness "d" on thermal conductivity (K) may be considered to be insignificant. Thus, the only quantities to examine are α and (dω/dP).…”

Thermal Transport Properties of Phonons in Halide Perovskites

“…Moreover, it is not clarified yet about how to tailor the specific phonon modes and strong phonon scattering in halide perovskites by using the engineering parameters, such as elements, compositions, phases, microstructures and even artificial patterns. [ 152 ] Such a knowledge will be also helpful for engineering carrier dynamics in optoelectronic devices.…”