Interplay of Crystallization and Amorphous Spinodal Decomposition during Thermal Annealing of Organic Photoactive Layers

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Siber, Maxime, Ronsin, Olivier J. J., Frey, Gitti L., Harting, Jens
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912773416419328
author Siber, Maxime
Ronsin, Olivier J. J.
Frey, Gitti L.
Harting, Jens
author_facet Siber, Maxime
Ronsin, Olivier J. J.
Frey, Gitti L.
Harting, Jens
contents Tailoring the nanomorphology of organic photoactive layers through a specialized chain of processing steps is an imperative challenge on the path towards reliable and performant organic electronic manufacturing. This hurdle generally proves delicate to be overcome, as organic materials can be subject to many different phase transformation phenomena that are able to interfere with each other and produce a wide variety of morphological configurations with distinct structural, mechanical, and optoelectronic properties. A typical combination of such mechanisms, which the present systems are often prone to, and which is complex to investigate experimentally at the nanoscale, is the phase separation resulting from the interplay between amorphous demixing and crystallization. In this work, an in-house Phase-Field modeling framework is employed to simulate and, consequently, explain the phenomenological behavior of a photoactive bulk heterojunction during a thermal annealing treatment. The model predictions are validated against available electron microscopy imaging of the nanostructural evolution during the process. It is demonstrated that the simulations can successfully provide a detailed comprehension of crystal nucleation and growth shaped by amorphous spinodal decomposition, so as to yield valuable insights for physically-based morphology control. In addition, this study shows the relevance of extensive thermodynamic and kinetic characterizations of organic semiconductor mixtures (e.g., phase diagram assessments, surface tension measurements, composition-dependent molecular diffusivity evaluations) for the associated field of research.
format Preprint
id arxiv_https___arxiv_org_abs_2512_16390
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Interplay of Crystallization and Amorphous Spinodal Decomposition during Thermal Annealing of Organic Photoactive Layers
Siber, Maxime
Ronsin, Olivier J. J.
Frey, Gitti L.
Harting, Jens
Materials Science
Tailoring the nanomorphology of organic photoactive layers through a specialized chain of processing steps is an imperative challenge on the path towards reliable and performant organic electronic manufacturing. This hurdle generally proves delicate to be overcome, as organic materials can be subject to many different phase transformation phenomena that are able to interfere with each other and produce a wide variety of morphological configurations with distinct structural, mechanical, and optoelectronic properties. A typical combination of such mechanisms, which the present systems are often prone to, and which is complex to investigate experimentally at the nanoscale, is the phase separation resulting from the interplay between amorphous demixing and crystallization. In this work, an in-house Phase-Field modeling framework is employed to simulate and, consequently, explain the phenomenological behavior of a photoactive bulk heterojunction during a thermal annealing treatment. The model predictions are validated against available electron microscopy imaging of the nanostructural evolution during the process. It is demonstrated that the simulations can successfully provide a detailed comprehension of crystal nucleation and growth shaped by amorphous spinodal decomposition, so as to yield valuable insights for physically-based morphology control. In addition, this study shows the relevance of extensive thermodynamic and kinetic characterizations of organic semiconductor mixtures (e.g., phase diagram assessments, surface tension measurements, composition-dependent molecular diffusivity evaluations) for the associated field of research.
title Interplay of Crystallization and Amorphous Spinodal Decomposition during Thermal Annealing of Organic Photoactive Layers
topic Materials Science
url https://arxiv.org/abs/2512.16390