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Observation and enhancement of visible photoluminescence of PECVD a‐SiOx:H (x < 2) thin films by microcavity effect

“…However, for the single layer sample presented here, the PL band due to tail-to-tail recombination could not be observed even at low temperatures. This behavior was explained in the basis of the dangling bond defect density of the sample [3].…”

“…H samples a-SiO x :H samples show strong room temperature visible PL property centered around a photon energy of 2.1 eV [3,[6][7][8]. The PL spectrum of a-SiO x :H thin film sample is exposed to alter due to the interference fringes resulting from multiple reflections between two interfaces of the single layer sample [3][4]13].…”

“…The PL spectrum of a-SiO x :H thin film sample is exposed to alter due to the interference fringes resulting from multiple reflections between two interfaces of the single layer sample [3][4]13]. In Fig.…”

“…Since the position of the 2.1 eV PL band of a-SiO x :H is independent of the band gap of the sample and its activation like temperature dependence, the 2.1 eV PL band was suggested to originate from intrinsic point defects of SiO 2 structure such as E' centers [3,6,15]. In SiO 2 structure, holes can easily be self trapped to form self trapped holes (STH) which are localized by the intrinsic defects of SiO 2 structure, such as oxygen vacancy defects (E' centers) [6,15].…”

“…The PL from a-SiO x :H single layers has been attributed mainly to the three recombination mechanisms: (1) the separation of two phases of a-Si:H and SiO 2 [5]; (2) the intrinsic defects of SiO x structure such as self trapped excitons (STE), non-bridging oxygen hole center (NBOHC) [5][6][7] and (3) the tail-to-tail radiative recombination [8]. The importance of deposition conditions and post deposition annealing treatment on the PL property of a-SiO x :H have been also studied [3,9]. The enhancement of PL from a-Si:H and its alloys by means of microcavity effect has been presented within many works [10][11][12][13], as well.…”