Enhancement of visible photoluminescence in the SiNx films by SiO2 buffer and annealing

Abstract

The authors report a simple method to significantly enhance the photoluminescence (PL) of SiNx films by incorporating a SiO2 buffer and annealing treatment under N2 protection. Strong visible PL is achieved with annealing temperature above 650°C. Optimal PL is obtained at 800°C. The composition and structure analysis reveal that strong PL is directly related to the content of the Si–O and Si–N bonds in the SiNx films. These bonds provide effective luminescent centers and passivate the interface between Si core and the surrounding oxide.

Inductively coupled plasma-assisted RF magnetron sputtering deposition of boron-doped microcrystalline Si films

“…3(a) represents the Raman scattering spectra of the samples deposited at different boron target powers. The dominant peak in all the spectra is located at approximately 520 cm −1 and is attributed to the transverse optical mode of crystalline Si, indicating that all the deposited films are in the state of crystalline phase [24].…”

Single-step, rapid low-temperature synthesis of Si quantum dots embedded in an amorphous SiC matrix in high-density reactive plasmas

“…Recently, Si quantum dots (QDs) embedded in a dielectric matrix have attracted a great deal of interest and have been a subject of intense scientific activities, owing to their immensely promising applications in the third generation photovoltaic solar cells [1][2][3][4][5]. The third-generation all-Si tandem photovoltaic solar cells, which rely on the quantum confinement effects in the embedded Si quantum dots, are expected to overcome the Shockley-Queisser limit of conventional solar cells and reach the high-energy conversion efficiency of 47.5% using three-cell tandem stacks [6,7].…”

“…Most publications to date have focused on the preparation of Si QDs embedded in amorphous SiO 2 or Si 3 N 4 matrices [1,8,9]. The typical preparation method involves the deposition of a single-layer Si-rich SiO 2 (or Si 3 N 4 ) or multi-alternating layers of Si-rich SiO 2 (or Si 3 N 4 )/quasistoichiometric SiO 2 (or Si 3 N 4 ) superlattice by chemical vapor deposition, and subsequent thermal annealing in the inert gas ambient in the quartz furnace at temperatures of up to 1100°C [1,8,9].…”

“…The typical preparation method involves the deposition of a single-layer Si-rich SiO 2 (or Si 3 N 4 ) or multi-alternating layers of Si-rich SiO 2 (or Si 3 N 4 )/quasistoichiometric SiO 2 (or Si 3 N 4 ) superlattice by chemical vapor deposition, and subsequent thermal annealing in the inert gas ambient in the quartz furnace at temperatures of up to 1100°C [1,8,9]. The plausible physical mechanism for the achievement of the Si QDs embedded in the SiO 2 (or Si 3 N 4 ) matrix in this method is due to the thermally activated phase separation and precipitation of Si nanocrystals in the matrix [7,9].…”

Hydrogenated amorphous silicon carbide thin films deposited by plasma-enhanced chemical vapor deposition

“…Amorphous and nanocrystalline silicon materials have recently attracted extensive research efforts as promising materials for applications in the fields of photovolataic solar cells, image sensors and thin film transistors [1,2]. When silicon nanocrystals are made very small (<~7 nm in diameter), they would behave as QDs due to the quantum confinement effect of carriers [3].…”