YANG Wooseok | 양우석

Assistant Professor of Chemical Engineering

제2공학관 25동 5층 25535A호

Research Areas

Solar to fuel conversion

Research Interests

One of the paramount challenges for a sustainable society is the conversion of solar energy into a vector suitable for storage. Solar energy can be stored with battery technology by converting it into electricity via photovoltaic (PV) cells; however, producing H2 fuel via photoelectrochemical (PEC) water splitting is a more efficient solution for long-term storage. To accelerate the deployment of solar H2, cost must be reduced while maintaining reasonable efficiency to realize solar H2 production at a commercial scale. The most important building block in PEC water splitting systems in terms of cost and performance is the light-absorbing semiconductor. Therefore, it is of significant importance that searching earth-abundant semiconductors for PEC water splitting as well as the development of cost-effective fabrication routes. Our research mainly focuses on H2 production via PEC water splitting, from the synthesis of emerging low-cost semiconductor materials to device fabrication and advanced characterizations.

Synthesis of emerging semiconductors for photoelectrochemical water splitting
The development of novel solution-based approaches to fabricate emerging semiconductor thin films is of our particular interest. We have performed the research on chalcogenide semiconductors for PEC water splitting, and tried to uncover the relationships between the synthesis conditions of the functional inks and the properties of the resulting materials (phase purity, morphology, optoelectronic properties, etc) for high device performance and stability.

Demonstration of highly efficient tandem devices for water splitting
The realization of efficient water splitting devices requires judicious combinations of each functional layer along with other semiconductor materials. We have tried to demonstrate efficient tandem devices consisting of two different light absorbers to enable efficient utilization of solar photons.

Advanced device characterizations for photoelectrochemical water splitting
As the understanding of the underlying photophysical and electrochemical processes is crucial, researchers have sought to develop various characterization methods for investigating PEC devices. In addition to the basic electrochemical characterization, we have also developed novel implementations of advanced characterization methods, such as electrochemical impedance spectroscopy, transient photocurrent, intensity-modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS), THz spectroscopy, etc. to get further insight on device physics.

Selected Publications

  1. Xi Zhang, Wooseok Yang*, Wenzhe Niu, Pardis Adams, Zhenbin Wang, S. David Tilley* “Thiol-amine-based Solution Processing of Cu2S Thin Films for Photoelectrochemical Water Splitting”, ChemSusChem, 2021, 10.1002/cssc.202101347 (co-corresponding author*)
  2. Wooseok Yang, Thomas Moehl, Erin Service, S. David Tilley* “Operando Analysis of Semiconductor Junctions in Multi-Layered Photocathodes for Solar Water Splitting by Impedance Spectroscopy”, Adv. Energy Mater., 2021, 11 (9), 2003569
  3. Wooseok Yang‡, Jaemin Park‡, Hyeok-Chan Kwon‡, Oliver S. Hutter, Laurie J. Phillips, Jeiwan Tan, Hyungsoo Lee, S. David Tilley, Jonathan D. Major and Jooho Moon* “Solar water splitting exceeding 10 % efficiency via low-cost Sb2Se3 photocathodes coupled with semitransparent perovskite photovoltaics”, Energy & Environ. Sci. 2020, 13, 4362-4370
  4. Wooseok Yang‡, Jin Hyun Kim‡, Oliver S. Hutter, Laurie J. Phillips, Jeiwan Tan, Jaemin Park, Hyungsoo Lee, Jonathan D. Major*, Jae Sung Lee*, and Jooho Moon* “Benchmark performance of low-cost Sb2Se3 photocathodes for unassisted solar overall water splitting”, Nat. Comm., 2020, 11, 861
  5. Wooseok Yang, Rajiv Ramanujam Prabhakar, Jeiwan Tan, S. David Tilley, Jooho Moon “Strategies for Enhancing Photocurrent, Photovoltage, and Stability of Photoelectrodes for Photoelectrochemical Water Splitting”, Chem. Soc. Rev., 2019, 48, 4979
  6. Hyungsoo Lee†, Wooseok Yang†, Jeiwan Tan, Yunjung Oh, Jaemin Park, and Jooho Moon, “Cu-doped NiO as an Effective Hole Selective Layer for High Performance Sb2Se3 Photocathode for Photoelectrochemical Water Splitting”, ACS Energy Lett., 2019, 4(5), 995 (co-first author†)
  7. Wooseok Yang, Hyeok-Chan Kwon, Jeiwan Tan, Hyungsoo Lee, Jaemin Park, Yunjung Oh, Seungmin Lee, Hyunyong Choi, Jooho Moon, “Time-Resolved Observation of Photo-Generated Charge Carrier Dynamics in Sb2Se3 Photocathodes for Photoelectrochemical Water Splitting”, ACS Nano, 2018, 12, 11088.
  8. Wooseok Yang, Jihoon Ahn, Yunjung Oh, Jeiwan Tan, Hyungsoo Lee, Jaemin Park, Hyeok-Chan Kwon, Juran Kim, William Jo, Joosun Kim, Jooho Moon, “Adjusting the anisotropy of 1D Sb2Se3 nanostructures for highly efficient photoelectrochemical water splitting”, Adv. Energy Mater., 2018, 8, 1702888 (Front Cover)
  9. Wooseok Yang, Yunjung Oh, Jimin Kim, Myung Jin Jeong, Jong Hyeok Park, Jooho Moon, “Molecular Chemistry Controlled Hybrid-ink Derived Efficient Cu2ZnSnS4 Photocathodes for Photoelectrochemical Water Splitting” ACS Energy Lett., 2016, 1, 1127
  10. Wooseok Yang, Yunjung Oh, Jimin Kim, Hyunchul Kim, Hyungjung Kim, Jooho Moon, “Photoelectrochemical Properties of Vertically-Aligned CuInS2 Nanorod Arrays Prepared via Template-Assisted Growth and Transfer” ACS Appl. Mater. & Interfaces, 2016, 8(1), 425

Professional Experience

2018-2019, 박사후 연구원 (연세대학교)
2019-2022, 박사후 연구원 (University of Zurich, Switzerland)