The Role of N–Si–O Defect States in Optical Gain from an a‐SiN_xO_y/SiO₂ Waveguide and in Light Emission from an n‐a‐SiN_xO_y/p‐Si Heterojunction LED

Abstract

Amorphous silicon oxynitride (a-SiN x O y ) film is a kind of new luminescent material, which exhibits highly efficient light emission from luminescent N-Si-O defect states. In this work, the measurements of steady-state photoluminescence (SSPL), temperature-dependent photoluminescence (TDPL), and nanosecond time-resolved photoluminescence (ns-TRPL) are combined to further verify the role of luminescent N-Si-O defect states on the performance of photoluminescence (PL), electro-luminescence (EL), and optical gain, etc., for both intrinsic and doped a-SiN x O y films. The results indicate that both PL and EL originate from luminescent N-Si-O defect states, which is totally different behavior from that observed from band tail states in normal amorphous semiconductors. In the case of device applications, the properties of optical gain in an a-SiN x O y / SiO 2 waveguide are investigated. Based on the signal of amplified spontaneous emission (ASE) coming from the edge of the waveguide, an optical gain coefficient higher than 100 cm À1 is obtained by using variable stripe length (VSL) measurements. For another application example, it is found that radiative recombination via luminescent N-Si-O defect states can also contribute to the EL observed from an n-a-SiN x O y /p-Si heterojunction LED, in which the light emission power efficiency is determined to be five times higher than that in an a-SiN x O y MIS LED.

A High-Performance SiO2/SiN x 1-D Photonic Crystal UV Filter Used for Solar-Blind Photodetectors

“…4(a), and this transition layer was also often observed in other references [18], [19]. The Si-O-N film has an extensive range of optical bandgap from 2.9 to 6.2 eV according to different references [20], [21], and hence exists significant absorption in the solar-blind region.…”

Luminescence Mechanism in Amorphous Silicon Oxynitride Films: Band Tail Model or N-Si-O Bond Defects Model

“…Based on the three-level energy band structure, we studied the optical gain property of our N-type a-SiN x O y films. The optical gain coefficient G∼102 cm −1 has been observed [69]. This kind of amplified emission can also be explained by the carrier recombination radiatively via the N-Si-O bond defect states.…”

“…We also investigated the performance of n-a-SiN x O y /p-Si hetero-junction (HJ) LED [30,69]. The phosphor doped n-a-SiN x O y (ρ∼2.5 Ω cm, µ∼1 cm 2 V −1 s −1 ) was deposited on the p-Si substrate to fabricate an ITO/n-a-SiN x O y /p-Si HJ LED, which was schematically shown in the inset of Figure 10A.…”

A Review: Preparation, Performance, and Applications of Silicon Oxynitride Film

“…SiN x O y film has performance between SiO 2 and Si 3 N 4 . Due to its excellent photoelectric performance, it has been widely used in optical devices, dielectric gate dielectric materials, and optical waveguide materials [118]. The SiN x O y film also has high chemical stability, high resistance to impurity diffusion, and water vapor permeability, which is highly promising for applications in barrier devices such as gas barriers [119].…”