Hao Chen

Hao Chen

Researcher in functional oxide films, probing defect-driven electronic and optical/transport properties using synchrotron X-ray spectroscopy and advanced methods.

Posts by Collection

portfolio

Defective WO3-x Thin Films

Understanding defective WO3-x thin films through complementary experimental techniques
Key Activities:
- Quantified defect concentrations using EDXS, XPS, and Auger spectroscopy
- Developed ellipsometry models to resolve depth-dependent dielectric profiles
- Linked XANES/EXAFS results to oxidation states, local coordination, and oxygen vacancies
- Implemented Python-based NNMF workflows to extract hidden components from large RIXS datasets
- Established SEM/AFM protocols for nanoscale morphology and surface analysis
- Correlated XRD and Raman spectroscopy to identify amorphous-to-crystalline transitions
- Measured electrical transport, relating conductivity to defect chemistry
- Probed ultrafast carrier dynamics using pump–probe transient absorption spectroscopy

Operando XAS Study of Novel Cathode Material for Solid Oxide Fuel Cells

Real-time investigation of functional cathode materials using synchrotron-based spectroscopy
Key Activities:
- Performed operando XAS to monitor electronic and structural evolution under working conditions
- Developed Python-based workflows to decouple thermal and chemical contributions in operando datasets

Controlled Growth and Characterization of Correlated Electron Systems

Thin film growth and electronic structure characterization using synchrotron-based spectroscopy
Key Activities:
- Optimized pulsed laser deposition for epitaxial growth and interface control in complex oxides
- Quantified film periodicity and interface sharpness using combined XRD/XRR analysis
- Validated composition and stoichiometry through complementary XPS and SEM–EDX measurements

3-Month Research Stay – ESRF (France)

Synchrotron-based experiments and user support
Key Activities:
- Trained in synchrotron instrumentation and advanced experimental techniques
- Performed X-ray spectroscopy experiments and data analysis
- Assisted beamline users during experimental campaigns

publications

Paper Title Number 4

Published in GitHub Journal of Bugs, 2024

This paper is about fixing template issue #693.

Recommended citation: Your Name, You. (2024). "Paper Title Number 3." GitHub Journal of Bugs. 1(3).
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talks

EOSAM: near-IR transparent conductive amorphous WO3-x thin layers by non-reactive RF-sputtering

Published:

With growing demand for transparent conductive materials, this work explores amorphous WO3-x thin films as a promising alternative. Smooth, compact films were fabricated by RF-sputtering and enhanced via post-annealing, leading to improved near-IR transparency and a competitive figure of merit, highlighting their potential for next-generation optoelectronic applications.

FISMAT: XAS and RIXS investigation of oxygen vacancy engineering in WO3-x films: from amorphous to crystalline phases

Published:

Quantitative non-negative matrix factorization (NNMF) analysis of RIXS datasets resolves mixed-valence tungsten states (W⁴⁺, W⁵⁺, W⁶⁺) in WO3-x, enabling extraction of the previously obscured W⁵⁺ component. The results show that W⁴⁺-rich configurations dominate optical absorption and electrical conduction, with infrared response consistent with small-polaron hopping between mixed-valence sites in amorphous WO3-x.

teaching

Teaching experience 1

Undergraduate course, University 1, Department, 2014

This is a description of a teaching experience. You can use markdown like any other post.

Teaching experience 2

Workshop, University 1, Department, 2015

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