Charge generation pathways of organic materials

Infographic figure showing five different ways in which charge carriers can be generated from their resting molecular orbital.

The researchers mapped the various pathways by which electrons can be excited from the highest occupied molecular orbital (HOMO) an organic material to the lowest unoccupied molecular orbital (LUMO) and beyond to ionization.  

While photo-induced charge separation (CS) between donor and acceptor materials (A), direct photoionization in single-component molecules (E) and non-resonant multiphoton ionization (NRMPI, D) are well-studied, the resonant multiphoton excitation pathways (B–C) had received little attention. 

In these states, electrons absorb multiple photons in succession, with each photon bumping the electron onto a higher but short-lived excited state before the next photon pushes it further. In NRMPI, the electron never lands on an excited state but is instead collectively pushed by multiple photons through ‘virtual’ states on the way to ionization.

Date:
05 December 2025
Credit:
Oyama et al., 2025

Copyright OIST (Okinawa Institute of Science and Technology Graduate University, 沖縄科学技術大学院大学). Creative Commons Attribution 4.0 International License (CC BY 4.0).

Download full-resolution image
Share on:
x icon facebook icon linkedin icon mail icon

Related Images

Comparison between computational modeling and actual embryo on gene regulation in the entire fruit fly embryo

  Dr. Garth Ilsley, in Prof Nicholas Luscombe’s Genomics and Regulatory Systems Unit at OIST and Assistant Professor Angela DePace at Harvard Medical School succeeded in modelling early regulation of development in the fruit fly Drosophila using a statistical approach that accurately predicts gene expression in the whole embryo. This study was published in the open access journal, eLIFE, on August 6th. This figure is comparison of calculated results from the model (upper half) with image data from an actual embryo (lower half). It can be seen that the mutations in stripes 3 and 7 due to the misexpression of kni (A) and hb (B) are consistent. (A) Misexpression of kni is seen as a thinner stripe 3, and stripe 3 is also cut when there are 2 copies of the transgene. (B) Misexpression of hb results in bulging, bending and cutting of stripe 3. Stripe 7 bulges when there are 2 copies of the transgene. Stripe 2 remains unaffected in both cases.