Applying Marcus theory to describe the carrier transports in organic semiconductors: Limitations and beyond

Abstract

Marcus theory has been successfully applied to molecular design for organic semiconductors with the aid of quantum chemistry calculations for the molecular parameters: the intermolecular electronic coupling V and the intramolecular charge reorganization energy λ. The assumption behind this is the localized nature of the electronic state for representing the charge carriers, being holes or electrons. As far as the quantitative description of carrier mobility is concerned, the direct application of Marcus semiclassical theory usually led to underestimation of the experimental data. A number of effects going beyond such a semiclassical description will be introduced here, including the quantum nuclear effect, dynamic disorder, and delocalization effects. The recently developed quantum dynamics simulation at the time-dependent density matrix renormalization group theory is briefly discussed. The latter was shown to be a quickly emerging efficient quantum dynamics method for the complex system.

Anomalous (Exergonic) Behavior in the Transfer of Electrons between Donors and Acceptors: Mobility, Energy, Caloric Capacity, and Entropy

“… 70 − 72 These semiconductors present a negative temperature coefficient of the mobility (dμ/d T < 0) under ambient conditions, which can be considered as a fingerprint of the “band-like” transport behavior. 73 The room-temperature hole mobilities obtained by eq 2 gives values of order of units cm 2 /(V s) (see Supporting Information , Figure S2), which are in good agreement with the reported data for pentacene 69 , 74 − 76 and rubrene. 70 , 72 , 74 Let us remark that the effective mass is not a quantity that can be easily experimentally determined which makes the estimation of μ 0 complicated.…”

Effect of Strong Intermolecular Interaction in 2D Inorganic Molecular Crystals

“…Since Marcus semiclassical theory usually leads to an underestimation of experimental mobility, we will mainly focus on the mobility calculated by quantum nuclear tunneling model in the following discussion. 59 The hole mobility reaches its maximum value (0.4 cm 2 V −1 s −1 ) in the b-axis orientation, which is comparable to that of many organic semiconductors and contradicts the viewpoint that the inorganic molecular crystals are insulating solids. 60−62 For the mobility of electrons, the maximum value (0.002 cm 2 V −1 s −1 ) is obtained along the a axis.…”

Alkylated Benzodithienoquinolizinium Salts as Possible Non-Fullerene Organic N-Type Semiconductors: An Experimental and Theoretical Study

“…Charge mobility is an important factor to be considered in organic semiconductors. Transport properties are commonly discussed with the aid of Marcus theory [ 55 ], though other approaches are also found in the literature [ 72 , 73 , 74 , 75 , 76 , 77 , 78 ].…”