Effect of temperature on the emission properties of quasi 2D glass-like carbon placed on silicon and silicon dioxide substrates

Abstract

In this work, in silico methods are used to study the temperature effect of the emission properties, including the electron work function, of quasi 2D glass-like carbon (GLC) films deposited on few/multi-layer Si/SiO2 substrates of two types. The equilibrium configuration of the structures under study at different temperatures is established by molecular dynamics (MD) method using reactive force field (ReaxFF) due to the polyatomic nature of supercells. The electronic structure is determined using the self-consistent charge density-functional based tight-binding (SCC-DFTB) method. The temperature range under consideration is 50–1000 K. The effect of one substrate layer and several substrate layers on the electronic structure and emission properties of GLC is considered. In the case of one layer of Si and SiO2, in fact, the functionalization of the GLC film occurs. This leads to a decrease in the work function by ∼ 6 % and ∼ 21 %, respectively, at a temperature of 300 K. As the temperature increased to 1000 K, the work function of the GLC with one SiO2 layer further decreased by ∼ 7 %. An increase in the substrate thickness to five Si layers and two SiO2 layers leads to a decrease in the work function by 7.3 % and 20.5 %, respectively. An increase in temperature leads to a change in the work function of the GLC with five Si substrate layers and two SiO2 layers by 0.2 % and 3.8 %, respectively.