Direct Electrical Measurements of Energy Bands in Organic Semiconductors by Device-Based Ballistic Carrier Emission Spectroscopy

Published

March 11, 2020

Author(s)

Hyuk-Jae Jang, Oleg A. Kirillov, John S. Suehle, Curt A. Richter

Abstract

Understanding the electronic structure of organic/molecular semiconductors and the energetics at their interfaces with metals is critical for organic-based electronics applications. Here we demonstrate that the energetics at metal/molecule interfaces can be electrically measured by ballistic charge carrier (both electron and hole) emission spectroscopy with a single three- terminal device in real operation, thus providing us with direct information on the electronic structures of molecular semiconductors such as their energy bandgap. The energy distribution of electronic states in the molecular semiconductors tailing into their energy bandgap is well described by Lorentzian function in our measurements. In spin-polarized carrier injection measurements, we observe little or no magnetoresistance signal in our magnetic tunnel transistors which indicates that spin filtering effects strongly subside either at the metal/molecule interfaces or in the organic layers.

Citation

The Journal of Physical Chemistry C

Volume

124

Issue

16

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.jpcc.0c00865

Local Download

Keywords

Organic semiconductors, Metal organic molecule interface, Ballistic charge carrier injection, Spin valve effect, Molecular band energetics

Citation

Jang, H. , Kirillov, O. , Suehle, J. and Richter, C. (2020), Direct Electrical Measurements of Energy Bands in Organic Semiconductors by Device-Based Ballistic Carrier Emission Spectroscopy, The Journal of Physical Chemistry C, [online], https://doi.org/10.1021/acs.jpcc.0c00865, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930040 (Accessed October 9, 2025)