Enhanced Current Transportation in Siliconriched Nitride (SRN)/Silicon-riched Oxide (SRO) Multilayer Nanostructure

Abstract

A novel structure of silicon-riched nitride (SRN)/silicon-riched oxide (SRO) is proposed and prepared using RF reactive magnetron co-sputtering. High temperature annealing of SRN/SRO multilayers leads to formation of Si nanocrystals (NC) from isolating SRN and SRO layers simultaneously, which efficiently improves carrier transport ability compared to conventional SRN/Si3N4 counterpart. Micro-Raman scattering analysis reveals that SRN layer has dominating number of denser and smaller Si NCs, while SRO layer has relatively less, sparser and bigger Si NCs, as confirmed by high resolution transmission electron microscopy observation. The substitute SRO layers for Si3N4 counterparts significantly increase the amount of Si NCs as well as crystallization ratio in SRN layers; while the average Si NC size can be well controlled by the thickness of SRN layers and the content of N, and hence an obvious stronger absorption in UV region for the novel structure can be observed in absorption spectra. The I-V characteristics show that the current of hybrid SRN/SRO system increases up to 2 orders of magnitude at 1 V and even 5 orders of magnitude at 4 V compared to that of SRN/Si3N4 structure. Si NCs in SiOy layers provide a transport pathway for adjacent Si NCs in SiNx layers. The obvious advantage in carrier transportation suggests that SRN/SRO hybrid system could be a promising structure and platform to build Si nanostructured solar cells.

Luminescent Devices Based on Silicon-Rich Dielectric Materials

“…Figure 11 shows the J(E) dependency for the SRN-LECs with R N = 5, 20, and 80. The conduction mechanism of the carriers in the SRN ilms was studied by analyzing the diferent reported mechanism including P-F conduction [88,89], TAT [90], and space charge limited current (SCLC) [91]. As observed in Figure 11, the TAT mechanism is dominating the carrier transport at both forward and reverse bias, and it can be ascribed to the defect states generated during the SRN deposition.…”

“…A model based on the trap-assisted tunneling carrier transport is shown with the EL radiative recombination process in the reference [34]. Figure 12 shows the experimental J-E data from SRO-LECs with Ro = 20 and 30 ited to the carrier transport mechanisms including Poole-Frenkel (P-F) conduction [88,89] and trapassisted tunneling (TAT) [90]. As can be observed, the TAT conduction mechanism predominates in the SRO-LEC with Ro = 30 (M30).…”