Electron transfer at thermally heterogeneous molecule-metal interfaces

Abstract

The rate of electron transfer between a molecular species and a metal, each at a different local temperature, is examined theoretically through implementation of a bithermal (characterized by two temperatures) Marcus formalism. Expressions for the rate constant and the electronic contribution to a heat transfer mechanism which is induced by the temperature gradient between molecule and metal are constructed. The system of coupled dynamical equations describing the electronic and thermal currents are derived and examined over diverse ranges of reaction geometries and temperature gradients. It is shown that electron transfer across the molecule-metal interface is associated with heat transfer and that the electron exchange between metal and molecule makes a distinct contribution to the interfacial heat conduction even when the net electronic current vanishes.

Upside/Downside statistical mechanics of nonequilibrium Brownian motion. I. Distributions, moments, and correlation functions of a free particle

“…which is averaged over the distribution ρ 0 (v) to obtain the expectation values), 52,53 evaluating Eqs. (22) and (23) gives the expected result:…”

“…The most common case is a process driven by two thermal sources (N = 2), and this system has been the focus of intensive investigation due to its relevance for vibrational heat conduction 7,10-20 and electron-transfer-induced heat transport. [21][22][23][24]50 In this article, the general derivations of the restricted properties are valid for arbitrary N. For simplicity, the results shown in all figures are for the N = 2 model.…”

Upside/Downside statistical mechanics of nonequilibrium Brownian motion. II. Heat transfer and energy partitioning of a free particle

“…While ∆E = 0 for an unrestricted ensemble at steady state, in this paper we investigate this quantity in the restricted case where ∆E can be nonzero. A process driven by two thermal sources (N = 2) is the most common case due to its relevance for heat transport in molecular systems, 12,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]61 and all numerical results in this article are for this scenario. The time-dependence of the heat obtained-by/released-into the system from baths 1 and 2 for a system driven by two sources is shown in Fig.…”

“…9,[12][13][14] Specifically, analyses of the ensembles generated by stochastic processes have been applied to obtain salient macro-features of a system such as free energy and work from a Markovian picture of its microscopic trajectory-based evolution. 14 For a system that is in contact with multiple thermal baths, 12,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] the answer to the fundamental partitioning question -what fraction of the total energy change is obtained from or released into each bath during activation and relaxation events? -has significant ramifications in the understanding of heat transfer kinetics.…”

Preface: Special Topic on Frontiers in Molecular Scale Electronics

“…These include aspects of electronic correlations, 6 magnetism, and spin-related effects. [7][8][9] Molecular vibrations, junction mechanics, and associated thermal effects have been analyzed experimentally and theoretically [10][11][12][13][14] and time resolved studies are also under way. [15][16][17] With such a wealth of phenomena, many of which are very specific to molecular junctions, it is not surprising that the field has motivated a significant amount of theoretical a) Electronic addresses: ferdinand.evers@physik.uni-regensburg.de and lv2117@columbia.edu work.…”