A5052171903- Silicon and Solar Cell Technologies
- Thin-Film Transistor Technologies
- Semiconductor materials and interfaces
- Integrated Circuits and Semiconductor Failure Analysis
- Semiconductor materials and devices
- Silicon Nanostructures and Photoluminescence
- Organic Light-Emitting Diodes Research
- Organic Electronics and Photovoltaics
- Advancements in Semiconductor Devices and Circuit Design
- Photovoltaic System Optimization Techniques
- CCD and CMOS Imaging Sensors
- Silicon Carbide Semiconductor Technologies
- Luminescence and Fluorescent Materials
- Infrared Target Detection Methodologies
- Ion-surface interactions and analysis
- Advanced Memory and Neural Computing
- Advanced Surface Polishing Techniques
- Firm Innovation and Growth
- Electrochemical Analysis and Applications
- Game Theory and Applications
- Advancements in Photolithography Techniques
- Nuclear Engineering Thermal-Hydraulics
- Image Processing Techniques and Applications
- Aerodynamics and Acoustics in Jet Flows
- Combustion and Detonation Processes
Australian National University
2015-2024
Shanghai Huali Microelectronics (China)
2021-2023
Chinese University of Hong Kong
2007-2020
University of Hong Kong
2020
Iowa State University
2016-2017
Institute of Microelectronics
2017
University of Warwick
2016
University of Manchester
2016
China University of Petroleum, East China
2014
Fudan University
2008
There are a number of existing models for estimating the charge states defects in silicon. In order increasing complexity, these (a) Fermi-Dirac distribution, (b) Shockley-Last model, (c) Shockley-Read-Hall and (d) Sah-Shockley model. this work, we demonstrate their consistency with general occupancy ratio α, show that parameter can be universally applied to predict both monovalent multivalent deep levels, under either thermal equilibrium or steady-state conditions carrier injection. The...
It is known that the interstitial iron concentration in silicon reduced after annealing wafers coated with plasma-enhanced chemical vapour deposited (PECVD) nitride films. The underlying mechanism for significant reduction has remained unclear and investigated this work. Secondary ion mass spectrometry (SIMS) depth profiling of performed on annealed iron-contaminated single-crystalline passivated PECVD SIMS measurements reveal a high uniformly distributed This accumulation film matches loss...
Herein, a systematic study of the electronic quality gallium‐doped p‐type silicon wafers from Czochralski‐grown ingots with melt recharging is presented. It found that in as‐grown state, contain interstitial iron concentrations range 3 × 10 9 –2 cm −3 , trend slightly higher toward tail end each ingot, and subsequently grown ingots. However, analysis effective lifetimes indicates iron–gallium pairs are not dominant recombination centers state. Moreover, when these subjected to tabula rasa...
Effective hydrogenation of interstitial iron in boron-doped multicrystalline silicon wafers is reported. The were annealed with plasma-enhanced chemical vapour deposited nitride films, at temperatures 400 °C – 900 and for times from minutes to hours. At low where a combined effect precipitation dissolved Fe expected, results show that the process dominates precipitation. concentrations reduce by more than 90% after 30-min anneal between 600 °C. most effective reduction occurs 700 °C, 99%...
Injection-dependent lifetime spectroscopy of both n- and p-type, Cr-doped silicon wafers with different doping levels is used to determine the defect parameters Cri CrB pairs, by simultaneously fitting measured lifetimes Shockley-Read-Hall model. A combined analysis two defects data on p-type samples enables a significant tightening uncertainty ranges parameters. The capture cross section ratios k = σn/σp are determined as 3.2 (−0.6, +0) 5.8 (−3.4, +0.6), respectively. Courtesy direct...
High-performance MoS<sub>2</sub> nanopillar arrays characterized with electron injection and light extraction were facilely developed applied in flexible inverted OLEDs.
This paper investigates the potential of three different methods-tabula rasa (TR), phosphorus diffusion gettering (PDG), and hydrogenation, for improving carrier lifetime in n-type Czochralski-grown upgraded metallurgical-grade (UMG) silicon samples. Our results show that lifetimes UMG wafers used this study were affected by both mobile metallic impurities as-grown oxygen precipitate nuclei. Thus, dissolution grown-in nuclei via TR removal PDG step found to significantly improve electronic...
Due to the low temperature processing constraint in silicon heterojunction (SHJ) solar cells, no defect engineering improve wafer quality is typically incorporated during cell fabrication. This means that high‐quality n‐type Cz wafers are required produce high‐efficiency cells. Herein, recent demonstrations of incorporating approaches, such as gettering and hydrogenation, into SHJ process flow for both p‐type surveyed. Defect on before fabrication can significantly low‐lifetime wafers,...
We investigated ring defects induced by a two-step anneal in n-type Czochralski-grown silicon wafers using combination of high spatial resolution Fourier Transform Infrared Spectroscopy (FTIR), micro-photoluminescence (PL) mapping, and micro-Raman mapping. Through FTIR measurements, we show the inhomogeneous loss interstitial oxygen with positive correlation inverse lifetime. Using high-resolution micro-PL are able to distinguish individual recombination-active precipitates within rings...
Silicon heterojunction solar cell fabrication incorporates a significant amount of hydrogen into the silicon wafer bulk, and injected is comparable to that introduced by nitride films during high-temperature firing step. In this work, origins processing have been identified. We demonstrate plasma treatment routinely included improve surface passivation considerably increases concentration in wafers. also show hydrogenated amorphous i/p+ stack more effective than i/n+ for bulk incorporation,...
Czochralski (Cz)‐grown upgraded metallurgical‐grade (UMG) silicon wafers degrade significantly during high‐temperature processes, eroding their appeal as a low‐cost alternative to conventional electronic‐grade wafers. However, the thermal degradation in UMG can be delayed by utilizing prefabrication annealing step. Based on this, high‐efficiency solar‐cell process is modified selecting single‐boron diffusion step and applying phosphorus‐doped polycrystalline films electron‐selective contacts...
We reported high‐performance organic light‐emitting diodes (OLEDs) with a maximum efficiency of 42.3 lm W −1 and color rendering index 92 by facilitating charge carrier transportation controlling the recombination zone. In addition, we demonstrated that inserting thin interlayer in emitting layer prevented energy transfer between blue green emission layers, providing relative chromatic‐stability OLEDs. Furthermore, device also exhibit rather low correlated temperature (2202 K), corresponding...
This study reports on the electronic properties of industrial phosphorus-doped n-type silicon ingots for photovoltaic applications grown using Recharged Czochralski method. The quality is assessed via carrier lifetime measurements, both directly and passivated wafers, implied open-circuit (iVOC), maximum power point (iVMPP) voltages. wafers are studied in as-grown state, after various high temperature steps, including Tabula Rasa, phosphorus diffusion gettering, boron diffusion. material...
Complete regeneration of boron-oxygen-related (BO) defects has been demonstrated on n-type upgraded metallurgical-grade (UMG) Czochralski-grown silicon heterojunction solar cells. Under accelerated conditions (93 suns, 220 °C), VOC fully recovered in 30–100 s and remained stable during a subsequent stability test. milder (3 180 the kinetics were slowed down by more than an order magnitude, but recovery was still complete stable. The stabilized UMG cells is 709 mV–722 mV, similar to...
This paper presents experimental studies on the formation of ring defects during high-temperature annealing in both electronic-grade and upgraded metallurgical-grade (UMG) Czochralski-grown silicon wafers. Generally, a faster onset defects, or shorter incubation time, was observed UMG samples ([Oi] = 6.3 × 1017 cm−3) comparison to 3.9 used this work. By applying tabula rasa (TR) treatment prior annealing, time can be increased for types We show that TR temperatures above 1000 °C are...
With the remarkable advances in semiconductor processing, devices such as solar cells have fewer and defects that impact their performance. Determination of currently limit device performance, predominantly by increasing charge carrier recombination rate, has become more challenging with standard methods like deep level transient spectroscopy. To circumvent this limitation, photovoltaic community is attempting to use measurement rates identify remaining defects, approach intrinsically...
Significant reductions in interstitial iron (Fei) concentrations occur during annealing Fe-containing silicon wafers with nitride films the temperature range of 250 °C–700 °C. The are known to release hydrogen step. However, co-annealed samples oxide films, which hydrogen-lean, changes Fei were much less significant. precipitation is ruled out as a possible explanation for significant reductions. passivation Fei, complexing monatomic H and isolated forming recombination-inactive hydride,...
This paper investigates and compares the impurity gettering effects of silicon nitride (SiN <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><sub>x</sub></i> ) films that are synthesized by plasma-enhanced chemical vapor deposition (PECVD) under various conditions. Both industrial- laboratory-scale PECVD systems employed to deposit SiN with a wide range properties (with refractive indices from 1.93 2.45 at 632 nm), which covers entire used for...
High-performance multicrystalline silicon (HP mc-Si) from directional solidification has become the mainstream industrial material for fabricating mc-Si based solar cells photovoltaic applications. Transition metal impurities are inherently contained in HP during ingot growth, and they one of major efficiency-limiting drawbacks. In this work, we investigate gettering transition metals (Cu, Ni, Fe, Cr) wafers along an industrial-standard p-type ingot, via examining concentration distribution...