Electron-excited luminescence of SiC surfaces and interfaces

Abstract

Recent advances in probing the electronic structure of SiC with electron-excited luminescence techniques reveal the presence of localized electronic states near its surfaces and interfaces. These localized states form not only as a result of interface chemical bonding but also due to the formation of new lattice polytypes. Such electronic features are sensitive to the conditions under which the SiC is processed, as well as the application of electrical or mechanical stress. These localized changes on a nanometre scale provide a new perspective to Schottky barrier formation, band alignment, and polytypism in SiC as well as its performance in electronic devices.

Minority Carrier Lifetime Measurements on 4H-SiC Epiwafers by Time-Resolved Photoluminescence and Microwave Detected Photoconductivity

“…The near-bandedge emission (NBE) decay (detected at 391 nm) showed a double exponential decay, where the slower component is typically ascribed to the minority carrier lifetime [6,7]. The defect-related PL band at 510 nm showed a more complex multi-exponential decay behavior and is typically reported to be related either to residual boron [8,9] or structural defects [10,11]. The MDP signal typically showed a single exponential decay, influenced by both electron and hole contributions [7].…”

Single-photon emitting diode in silicon carbide

“…These common characteristics suggest a common origin. Firstly, it is known that stacking faults (SFs) often form close to the surface during post-growth surface processing 26 . The variation in size and type of these SFs could explain the large ZPL variability 27 .…”

Low-dimensional SiC nanostructures: Fabrication, luminescence, and electrical properties

“…This is in contrast to porous Si [5,24] and Si nanocrystals [25][26][27][28] from which quantum confinement can be more easily observed. As a binary compound, silicon carbide has complex surface states and structures [29][30][31][32]. The main reasons why quantum confinement is not easily achieved in SiC are that there are many surface or defect states which dominate the luminescence and that the SiC nanocrystals are too large [17].…”