Proton diffusion in ceramic fuel cells 陶瓷燃料电池中的质子传导
Ceramic proton conductors are promising electrolyte materials in energy devices such as intermediate temperature solid-oxide fuel cells. However, the fundamental understanding about the relationship between the material structure and the proton transport process is still lacking, eliminating the enhancement of proton conductivity and thus the device performance. We systematically tune the crystal structure and phonon frequency in proton conductors by modulating the lattice strain using high pressure or epitaxial film growth, and study the correlation between crystal structure, lattice vibration and proton conductivity.
陶瓷质子导体是中温固体氧化物燃料电池等能源器件电解质的优秀候选材料。然而，当前仍然缺乏对材料结构和质子传输过程之间关系的完善理论理解，限制了材料质子电导率以及器件性能的提升。我们通过使用高压或外延膜生长的方法来调控晶格应变，从而系统地调节质子导体中的晶体结构和声子频率，并研究晶体结构、晶格振动与质子电导率之间的联系。
Representative publications:
- P. Du, N. Li, X. Ling, Z. Fan, A. Braun, W. Yang, Q. Chen, A. Yelon, Optimizing the Proton Conductivity with the Isokinetic Temperature in Perovskite-Type Proton Conductors According to Meyer–Neldel Rule, Advanced Energy Materials 12 (2022) 2102939.
- A. Braun, Q. Chen, Experimental neutron scattering evidence for proton polaron in hydrated metal oxide proton conductors, Nature Communications 8 (2017) 15830.
- Y. Gao, A.M. Nolan, P. Du, Y. Wu, C. Yang, Q. Chen, Y. Mo, S.-H. Bo, Classical and Emerging Characterization Techniques for Investigation of Ion Transport Mechanisms in Crystalline Fast Ionic Conductors, Chemical Reviews 120 (2020) 5954–6008. (ESI Highly Cited Paper)
Charge carrier transport in perovskite solar cells 钙钛矿太阳能电池的电荷载流子传输
Metal halide perovskites are applied in optoelectronic devices such as solar cells and light-emitting diodes. Despite the intensive research in the past decade, the relation between material and device structure on the charge carrier behavior are still under debate. We investigate the effects of crystal structure, microstructure and device structure on the photogenerated charge carriers and relevant photophysical processes.
金属卤化物钙钛矿可应用于光电器件，如太阳能电池和发光二极管中。尽管在过去十年中进行了深入的研究，但材料和器件结构与电荷载流子行为之间的关系仍存在争议。我们研究晶体结构、微观结构和器件结构对光生载流子和相关光物理过程的影响。
Representative publication:
- Y. Wang, M.-R. Ahmadian-Yazdi, Y. Ni, Y. Jiang, M. Eslamian, Z. Jin, Q. Chen, Boosted Charge-Carrier Transport in Triple-Cation Perovskites by Ultrasonic Vibration Post Treatment, Advanced Electronic Materials (2022) 2101286.
- C. Yang, P. Du, Z. Dai, H. Li, X. Yang, Q. Chen, Effects of Illumination Direction on the Surface Potential of CH3NH3PbI3 Perovskite Films Probed by Kelvin Probe Force Microscopy, ACS Applied Materials & Interfaces 11 (2019) 14044–14050.
In situ spectroscopic methods for nanoscale material chemistry and physics 材料物理与化学原位光谱表征方法
To investigate the fundamental physical- and chemical-processes in energy materials and devices, we develop and use complementary in situ experimental techniques, including vibrational spectroscopies, X-ray and neutron scattering, and scanning probe microscopies. These microscale probes are combined with conventional electrical and electrochemical characterization of materials at macro-scale. Our novel findings help to design better materials in the future.
为了研究能源材料与器件中的基本物理和化学过程，我们开发并使用原位实验表征方法，将振动光谱、X射线与中子散射、扫描探针显微镜等微观测试方法与常规电学、电化学宏观表征手段相结合，为高性能材料与器件设计服务。
Representative publication:
- Z. Zhao, X. Ling, F. El Gabaly, M. Grass, N. Jabeen, D. Jones, Z. Liu, B.S. Mun, A. Braun, Q. Chen, Observation of Potential-Induced Hydration on the Surface of Ceramic Proton Conductors Using In Situ Near-Ambient Pressure X-ray Photoelectron Spectroscopy, The Journal of Physical Chemistry Letters 13 (2022) 2928–2933.
- Q. Chen, F. El Gabaly, F. Aksoy Akgul, Z. Liu, B.S. Mun, S. Yamaguchi, A. Braun, Observation of oxygen vacancy filling under water vapor in ceramic proton conductors in situ with ambient pressure XPS, Chemistry of Materials 25 (2013) 4690–4696.