Low temperature plasma processing of nc-Si/a-SiN_x:H QD thin films with high carrier mobility and preferred (220) crystal orientation: a promising material for third generation solar cells

Abstract

The nc-Si-QDs/a-SiNx:H (∼5.7–1.3 nm) thin-films grown by low-temperature Inductively-coupled plasma, possess high carrier-mobility, electrical-conductivity, photosensitivity and preferred (220) crystal orientation, suitable for third-generation solar cells.

Silicon Nanocanyon: One-Step Bottom-Up Fabrication of Black Silicon via in-Lasing Hydrophobic Self-Clustering of Silicon Nanocrystals for Sustainable Optoelectronics

“…This restructuring was performed through reconstruction of the microstructure from amorphous to polycrystalline and is based on lasers with a UV wavelength shorter than the Si band gap. 41,42 Visible (vis) wavelength lasers also show a similar effect as that demonstrated by UV lasers because of a small absorption peak near 400 nm, which corresponds to the surface plasmon resonance mode of the Si NCs. 43 However, in this method, such laser sources are inappropriate for generating the hydrophobic clustering effect of Si NCs because the NCs are instantaneously transformed into a continuous Si layer without individual clustering.…”

“…Because Si NCs exhibit a strong absorption for short wavelengths below 300 nm (magenta region in Figure a), conventional laser-induced annealing processes, such as low-temperature polycrystallization and excimer laser annealing, were used to improve the electron mobility in the fabrication of thin-film transistors. This restructuring was performed through reconstruction of the microstructure from amorphous to polycrystalline and is based on lasers with a UV wavelength shorter than the Si band gap. , Visible (vis) wavelength lasers also show a similar effect as that demonstrated by UV lasers because of a small absorption peak near 400 nm, which corresponds to the surface plasmon resonance mode of the Si NCs . However, in this method, such laser sources are inappropriate for generating the hydrophobic clustering effect of Si NCs because the NCs are instantaneously transformed into a continuous Si layer without individual clustering.…”

“…The width [full width at half-maximum (fwhm)] of the XRD peak corresponding to the (111) crystal plane of black Si was 0.1507°, which is smaller than that of a Si NC (0.2295°); this implies that the Si grains grew to approximately 95 nm in the laser sintering process according to the Debye–Scherrer equation. The broad and slight increase in the XRD intensity around 22° is caused by a background effect of the glass substrate through the submicron valleys. , The EDXS analysis shown in the inset of Figure c provides the spatial distribution of Si in the laser-irradiated region compared to the surrounding Si NCs. It was found that the oxidation of black Si was limited during its formation, which followed the thermal melting and clustering, because there was no change in the concentration and distribution of Si in the black Si region when compared to the surrounding area.…”

Rapid synthesis of nc-Si/a-SiNx:H QD thin films by plasma processing for their cost effective applications in photonic and photovoltaic devices

“…Nanocrystalline siliconnitride (nc-Si/a-SiN x :H) thin lms, in which siliconnanocrystals (Si-nc) that exhibit a quantum size effect are embedded in a-SiN x :H dielectric matrix, have attracted considerable research interest due to their potential applications in solar cells, thin lm transistors and light-emitting devices. [11][12][13][14][15] Silicon-nitride (SiN x ) is being introduced as a material with a high dielectric constant, high strength over a wide temperature range, and a low tunneling barrier, as well as outstanding chemical inertness. Besides these, it has excellent inherent antireection and surface passivation properties which are very important for the enhancement of device performance.…”

Large‐scale data principal component analysis of phase transition from a‐Si:H to nc‐Si:H using PECVD optical emission spectra

“…Subsequently, the concept of the principal component analysis (PCA) in large-scale analysis [21][22][23][24][25][26] was used to correlate OES data and the resultant nc-Si:H film structures properties such as crystallisation rate (88.6%) and crystallised size (2.56 nm). In addition, the health value [25][26][27][28] was calculated and associated with the nc-Si:H film measurements.…”