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A Study of Temperature‐Dependent Photoluminescence from As‐Deposited and Heavy‐Ion‐Irradiated Plasma‐Enhanced Chemical Vapor Deposition‐Grown Si‐Rich a ‐SiN x :H Thin Films
Author(s) -
Gupta Harsh,
Plantevin Olivier,
Bommali Ravi K.,
Ghosh Santanu,
Srivastava Pankaj
Publication year - 2020
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.201900378
Subject(s) - photoluminescence , dangling bond , materials science , luminescence , thin film , chemical vapor deposition , silicon , analytical chemistry (journal) , quenching (fluorescence) , silicon nitride , irradiation , plasma enhanced chemical vapor deposition , chemistry , nanotechnology , optoelectronics , optics , fluorescence , physics , chromatography , nuclear physics
Temperature‐dependent photoluminescence (PL) measurements in the range of 10–300 K are carried out on silicon‐rich hydrogenated silicon nitride films deposited by plasma‐enhanced chemical vapor deposition. The in situ formation of Si quantum dots (QDs) with an average size of 3.5 nm is observed. The composition of thin films is estimated by Rutherford backscattering and ellipsometry. Broad PL spectra from thin films are decomposed into contributions from Si QDs, N dangling bonds (DBs), and Si DBs ( K ‐centers). At a low temperature, a strong PL can be observed, its quenching with increase in temperature is explained by the thermal activation of nonradiative decay mechanisms. Further, temperature‐dependent PL for swift heavy‐ion‐irradiated films shows similar quenching with increase in temperature. However, the effect of irradiation on the luminescence mechanisms of a ‐SiN x :H is revealed at low temperatures (<120 K) only, whereby a relatively narrow peak around 2.0 eV emerges. These results clearly show the role of radiative defects in the luminescence from Si‐rich silicon nitride.