# Temperature-dependent stability of polytypes and stacking faults in SiC: reconciling theory and experiments

## TL;DR

This study resolves a long-standing paradox by demonstrating how SiC polytypes' stability varies with temperature, aligning theoretical predictions with experimental data and informing better crystal growth practices.

## Contribution

The paper presents a temperature-dependent polytypic diagram for SiC, incorporating van der Waals corrections, reconciling theory with experiments, and analyzing stacking fault stability.

## Key findings

- Temperature influences SiC polytype stability through hexagonality effects.
- Theoretical results align with experimental observations of stacking faults.
- Lower deposition temperatures reduce stacking faults in SiC crystals.

## Abstract

The relative stability of SiC polytypes, changing with temperature, has been considered a paradox for about thirty years, due to discrepancies between theory and experiments. Based on ab-initio calculations including van der Waals corrections, a temperature-dependent polytypic diagram consistent with the experimental observations is obtained. Results are easily interpreted based on the influence of the hexagonality on both cohesive energy and entropy. Temperature-dependent stability of stacking faults is also analyzed and found to be in agreement with experimental evidences. Our results suggest that lower temperatures during SiC crystal deposition are advantageous in order to reduce ubiquitous stacking faults in SiC-based power devices.