Electronic Coupling between the Unoccupied States of the Organic and Inorganic Sub-Lattices of Methylammonium Lead Iodide a Hybrid Organic-Inorganic Perovskite Single Crystal

TL;DR

This study reveals electronic coupling between organic and inorganic sub-lattices in methylammonium lead iodide perovskite, challenging previous assumptions of inertness and providing insights into its opto-electronic properties.

Contribution

It demonstrates, using resonant Auger electron spectroscopy, that the organic cation actively participates in electronic processes within the perovskite.

Findings

Evidence of electronic coupling between organic and inorganic sub-lattices.

Contradicts previous beliefs that the organic cation is electronically inert.

Implications for electron dynamics and opto-electronic functionality.

Abstract

Organic-inorganic halide perovskites have been intensively re-investigated due to their applications, yet the opto-electronic function of the organic cation remains unclear. Through organic-selective resonant Auger electron spectroscopy measurements on well-defined single crystal surfaces, we find evidence for electronic coupling in the unoccupied states between the organic and inorganic sub-lattices of the prototypical hybrid perovskite, which is contrary to the notion based on previous studies that the organic cation is electronically inert. The coupling is relevant for electron dynamics in the material and for understanding opto-electronic functionality.