Dresden 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

HL: Fachverband Halbleiterphysik

HL 13: 2D Materials III – Interlayer excitons

HL 13.1: Talk

Monday, March 9, 2026, 16:45–17:00, POT/0081

Robust Interlayer Exciton Interplay in twisted Van der Waals Heterobilayer and Heterotrilayer on a Broadband Bragg Reflector up to Room Temperature — •Bhabani Sankar Sahoo, Shachi Machchhar, Avijit Barua, Martin Podhorsky, Chirag Chandrakant Palekar, and Stephan Reitzenstein — Technische Universität Berlin, Berlin, Germany

The MoSe2/WSe2/WSe2 Heterotrilayer (HTL) shows higher interlayer exciton (IX) emission intensity compared to the MoSe2/WSe2 heterobilayer (HBL) due to the additional WSe2 monolayer in the HTL, which improves interlayer coupling and provides additional radiative pathways. However, its coupling strength and thermal stability with increasing temperature remain unexplored. Here, we fabricate HTL and HBL using H-type stacking with twist angle of 55 and 50 for the MoSe2/WSe2 and WSe2/WSe2 heterostructures (HS) on the chirped distributed Bragg reflectors (cDBRs) centered at 800 nm. Photoluminescence (PL) emission at 4K shows that HTL exhibits more than 10-fold higher intensity compared to HBL. The temperature-dependent valley polarization reveals the interplay of triplet and singlet IX in the PL emission of the HBL and Indicates the influence of band modulation on the PL emission of the HTL. The temperature-dependent lifetime further provides insights into the different decay processes in both the HS, highlights the variations in optical performance between HTL and HBL HS with temperature. Additionally, through the combined effect of controlled stacking angles and the use of cDBR substrate, we successfully achieve room temperature IX across both regions of HS.

Keywords: Interlayer Exciton; Heterotrilayer; Heterobilayer; Bragg Reflectors; Optoelectronics