Stark Control of Electrons Across the Molecule-Semiconductor Interface

TL;DR

This paper demonstrates that the Stark Control of Electrons at Interfaces (SCELI) scheme can universally manipulate electron dynamics across molecule-semiconductor interfaces using ultrafast laser pulses, regardless of energy level alignment.

Contribution

The study extends SCELI's applicability to molecule-semiconductor interfaces, showing it induces charge transfer independently of energy alignment and outperforms resonant photoexcitation methods.

Findings

SCELI induces interfacial charge transfer regardless of energy level alignment.

Charge transfer rate via SCELI is faster than resonant photoexcitation.

SCELI operates effectively with non-resonant, non-ionizing ultrafast laser pulses.

Abstract

Controlling matter at the level of electrons using ultrafast laser sources represents an important challenge for science and technology. Recently we introduced a general laser control scheme (the Stark Control of Electrons at Interfaces or SCELI) based on the Stark effect that uses the subcycle structure of light to manipulate electron dynamics at semiconductor interfaces [{Phys. Rev. B \textbf{98}, 121305 (2018)}]. Here, we demonstrate that SCELI is also of general applicability in molecule-semiconductor interfaces. We do so by following the quantum dynamics induced by non-resonant few-cycle laser pulses of intermediate intensity (non-perturbative but non-ionizing) across model molecule-semiconductor interfaces of varying level alignments. We show that SCELI induces interfacial charge transfer regardless of the energy level alignment of the interface and even in situations where charge exchange is forbidden via resonant photoexcitation. We further show that the SCELI rate of charge transfer is faster than those offered by resonant photoexcitation routes as it is controlled by the subcycle structure of light. The results underscore the general applicability of SCELI to manipulate electron dynamics at interfaces on ultrafast timescales.