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Light emitting mechanisms in Si‐rich SiN x films with different silicon nitride stoichiometry
Author(s) -
Torchynska Tetyana,
Vergara Hernandez Erasto,
Khomenkova Larysa,
Slaoui Abdelilah
Publication year - 2017
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201600670
Subject(s) - photoluminescence , materials science , silicon , stoichiometry , silicon nitride , analytical chemistry (journal) , annealing (glass) , ellipsometry , chemical vapor deposition , thin film , optoelectronics , nanotechnology , chemistry , chromatography , composite material
Silicon‐rich silicon nitride films with different stoichiometry were grown on the silicon substrate using the plasma‐enhanced chemical vapor deposition. The excess silicon content in the films was monitored via varying the NH 3 /SiH 4 gas flow ratio from 0.45 up to 1.0. High‐temperature annealing was employed to produce the silicon nanocrystals (NCs) in the films and to enhance the photoluminescence in the range of 1.6–2.9 eV. Optical parameters of films were estimated by means of spectroscopic ellipsometry. Photoluminescence (PL) and its temperature dependences were studied as well. PL spectra were found to be complex due to the contribution of several radiative channels in the emission process. It was determined that their competition leads to the non‐monotonous variation of total PL peak position with the increase of Si excess content. The analysis of PL temperature dependencies has revealed that the “blue–orange” emission is owing to the radiative host defects, whereas the “red” PL band is caused by the exciton recombination in Si NCs. The way to control emission is discussed.