The Vanishing Confinement Regime in THz HgTe Nanocrystals Studied Under Extreme Conditions of Temperature and Pressure
Résumé
While HgTe nanocrystals (NCs) in the mid infrared have reached a high maturity, their far infrared counterparts remain far less studied, raising the need for an in-depth investigation of the material before efficient device integration can be considered. Here, we explore the effect of temperature and pressure on the structural, spectroscopic and transport properties of HgTe NCs displaying an intraband absorption at 10 THz. The temperature leads to a very weak modulation of the spectrum as opposed to what was observed for strongly confined HgTe NCs. HgTe NC films present ambipolar conduction with a clear prevalence of electron conduction as confirmed from transistor and thermoelectric measurements. Under pressure application, the material undergoes phase transitions from the zinc blende to cinnabar and later to rock salt that we reveal using joint Xray diffraction and infrared spectroscopic measurements. We discuss how the pressure existence domain of each phase is affected by the particle size.
| Origine | Fichiers produits par l'(les) auteur(s) |
|---|