Nanoscale Thermal Cloaking in Silicon Film: A Molecular Dynamic Study.

Jian Zhang,Wenbo Sun,Haochun Zhang,Dong Zhang,Qi Wang

doi:10.3390/ma15030935

Abstract

Nanoscale thermal shielding is becoming increasingly important with the miniaturization of microelectronic devices. They have important uses in the field of thermal design to isolate electronic components. Several nanoscale thermal cloaks based on graphene and crystalline silicon films have been designed and experimentally verified. No study has been found that simultaneously treats the functional region of thermal cloak by amorphization and perforation methods. Therefore, in this paper, we construct a thermal cloak by the above methods, and the ratio of thermal cloaking and response temperature is used to explore its cloaking performance under constant and dynamic temperature boundary. We find that compared with the dynamic boundary, the cloaking effect produced under the constant boundary is more obvious. Under two temperature boundaries, the thermal cloak composed of amorphous and perforated has a better performance and has the least disturbance to the background temperature field. The phonon localization effect produced by the amorphous structure is more obvious than that of the perforated structure. The phonon localization of the functional region is the main reason for the cloaking phenomenon, and the stronger the phonon localization, the lower the thermal conductivity and the more obvious the cloaking effect. Our study extends the nanoscale thermal cloak construction method and facilitates the development of other nanoscale thermal functional devices.

Highlights

The “invisibility cloak” that appears in fiction has always attracted the interest of researchers
Compared to the dynamic temperature boundary, the cloaking effect produced under the constant temperature boundary is more obvious
The reason is that the average temperature of the dynamic boundary at the same time is much lower than the temperature of the constant boundary, and the heat flux transferred in the whole system is small, resulting in an insignificant cloaking effect

Summary

Introduction

The “invisibility cloak” that appears in fiction has always attracted the interest of researchers. With the emergence of the theory of transformation optics [1], researchers successfully designed an optical thermal cloak and experimentally verified it with the help of metamaterials. With the emergence of transformation thermotics and thermal metamaterials, the thermal cloak greatly attracted the interest of researchers. Based on the theory of transformation thermotics, researchers have constructed a number of varieties of thermal functional devices: for instance, thermal cloak [3,4,5,6,7,8,9,10,11,12], thermal concentrator [13,14], thermal illusion [15,16,17,18], thermal camouflage [19,20,21,22,23,24,25], thermal rotator [26], and encrypted thermal printing [27]. Our study extends the nanoscale thermal cloak construction method, which can promote its engineering application

Model and Methodology

Potential Energy Model

Simulation Process

The Cloaking Performance

The Cloaking Mechanism

Conclusions