Yi Ren

ESR 2.2 Yi REN is a PhD student in Ångström Solar Center of Uppsala University

His topic is to use sputtering based methods for the formation of CZTS absorber, which is used as the alternative material to CIGS based PV technology, and the chemical composition and band alignment of this material will be typically studied during his PhD.  Prior to starting his PhD, he finished his bachelor study in Material Science and Engineering in the University of Science and Technology Bejing in China. He also took a Masters study in Material Engineering in the University of K.U. Leuven, in Belgium. It was a very interesting experience for him to have his master study in Leuven, where he touched CZTS material for the first time. He did his master thesis – “CZTSSe absorber formation from metallic sputtered layers” – at imec, with different characterization methods, such as Scanning Electron Microscopy, Energy Dispersive X-Ray Spectroscopy, X-Ray Diffraction, Current-Voltage measurement, etc. The challenges and the mysteries of this material attracted the researcher attention. Yi Ren chose to work in the KESTCELL project and Ångström solar center to continue on working with CZTS, and he believes he can learn a lot from both, science and the passionate researchers he is working with.

Papers:

  1. B. Vermang, Y. REN, O. Donzel-Gargand, C. Frisk, J. Joel, P. Salomé, J. Borme, S. Sadewasser, C. Platzer-Björkman and M. Edoff, “Rear Surface Optimization of CZTS Solar Cells by Use of a Passivation Layer with Nano-Sized Point Openings”, in: IEEE J. Photovolt. 6(1) 2016, 332-336. DOI: 10.1109/JPHOTOV.2015.2496864
  2. C. Frisk, Y. REN, S.-Y. Li, C. Platzer-Björkman, “CZTS solar cell device simulations with varying absorber thickness, in Photovoltaic Specialist Conference (PVSC)”, 2015 IEEE 42nd, DOI: 10.1109/PVSC.2015.7355794.
  3. J.K. Larsen, J.J.S. Scragg, C. Frisk, Y. REN and C. Platzer-Björkman, “Potential of CuS Cap to Prevent Decomposition of Cu2ZnSnS4 During Annealing”, In: Phys. Status Solidi A, 212(12), 2015, 2843-2849. DOI: 10.1002/pssa.201532420
  4. J.K. Larsen, S.-Y. Li, J. J. S. Scragg, Y. REN, C. Hägglund, M. D. Heinemann, S. Kretzschmar, T. Unold, C.Platzer-Björkman. Interference effects in photoluminescence spectra of Cu2ZnSnS4 and Cu (In, Ga) Se2 thin films. Journal of Applied Physics. 2015. Vol. 118. 35307. DOI: 10.1063/1.4926857
  5. J.MÁRQUEZ-PRIETO, Y. REN, R.W.Miles, N.Pearsall, I.Forbes, “The influence of precursor Cu content and two-stage processing conditions on the microstructure of Cu2ZnSnSe4”. Thin Solid Films, Vol.582,2015. DOI: 10.1016/j.tsf.2014.11.02
  6. K. Rudisch, Y. REN, C. Platzer-Björkman and J.J. Scragg, “Order-Disorder Transition in B-type Cu2ZnSnS4 and Limitation of Ordering Through Thermal Treatments”, in Appl. Phys. Lett. 108(23) 2016, 231902. DOI: 10.1063/1.4953349.
  7. S. VAN DUREN, Y. REN, J.Scragg, J.Just, T.Unold. Raman spectroscopy study on in-situ monitoring of Cu2ZnSnS4 synthesis. IEEE 2015 conference proceedings. DOI:10.1109/PVSC.2015.7355638
  8. S.-Y. Li, C. Hägglund, Y. REN, J. Scragg, J.K. Larsen, C. Frisk, K. Rudisch, S. Englund, C. Platzer-Björkman, “Optical Properties of Reactively Sputtered Cu2ZnSnS4 Solar Absorbers Determined by Spectroscopic Ellipsometry and Spectrophotometry”, In: Sol. Energy Mater. Sol. Cells, 149 (2016), 170-178. DOI: 10.1016/j.solmat.2016.01.014
  9. Y. REN, J. J. Scragg, T. Ericson, T. Kubart and C. Platzer-Björkman. “Reactively sputtered films in the CuxS-ZnS-SnSy system: from metastability to equilibrium”, Thin Solid Films. Vol.582, 2015. DOI: 10.1016/j.tsf.2014.10.076
  10. Y. REN, J.J.S. Scragg, M. Edoff, J.K. Larsen and C. Platzer-Björkman, “Evolution of Na-S(-O) Compounds on the Cu2ZnSnS4 Absorber Surface and Their Effects on CdS Growth”, in: ACS Applied Materials & Interfaces, 2016. DOI:10.1021/acsami.6b04978
  11. Y. REN, J.J. Scragg, C Frisk, J K Larsen, S-Y Li, C Platzer-Björkman. Influence of the absorber thickness on CZTS solar cell. Physica Solidi Status (A). 2015. DOI:10.1002/pssa.201532311.

Conferences:

B. Vermang, Y. Ren, O. Donzel-Gargand, C. Frisk, J. Joel, P. Salomé, J. Borme, S. Sadewasser, C. Platzer-Björkman, and M. Edoff, “Rear surface optimization of CZTS solar cells by use of a passivation layer with nano-sized point openings”, Presented at IEEE PVSC. New Orleans, US. 2015. (Oral).

S. van Duren, Y. Ren, J. Scragg, J. Just, T. Unold”, Raman spectroscopy study on in-situ monitoring of Cu2ZnSnS4 synthesis” Presented at IEEE PVSC. New Orleans, US. 2015. (Oral).

J. Márquez-Prieto, Y. Ren, R.W. Miles, N. Pearsall and I. Forbes, “The Influence of Precursor Cu Content and Two-Stage Processing Conditions on the Microstructure of Cu2ZnSnSe4 and Cu2SnSe3″, Presented at E-MRS Spring Meeting, Lille, France, 2014(Poster)

Y. Ren, J. J. Scragg, T. Ericson, T. Kubart, C, Platzer-Björkman. Reactively sputtered films in the CuxS-ZnS-SnSy system: from metastability to equilibrium”, Presented at EMRS , Lille, France, 2014(Poster)

C. Frisk, Y. Ren, S.Y. Li, C .Platzer-Björkman, “CZTS Solar Cell Device Simulations with Varying Absorber Thickness. IEEE PVSC”, Presented at New Orleans, US. 2015. (Poster).

S. van Duren, Y. Ren, J. Scragg, J. Just, T. Unold, “Temperature dependent Raman scattering of CuS, ZnS, SnxSy, CuxSnSy and Cu2ZnSnS4 for in-situ process control”, Presented at EU PVSEC. Hamburg, Germany. 2015. (Poster).

S.Y Li, C. Hägglund, Y. Ren, J. J. Scragg, J. K. Larsen, and C. Platzer-Björkman “Optical properties of reactively sputtered Cu2ZnSnS4 thin films studied using spectral ellipsometry and spectrophotometer”, Presented at EMRS, Lille, France, 2016 (Oral)

Y. Ren, J.J.S. Scragg, C. Frisk, J.K. Larsen, S.-Y. Li, C. Platzer-Björkman, “Influence of Influence of the absorber thickness on CZTS solar cell”, Presented at MRS San Fransico, US, 2015 (Poster).

Y. Ren, J.J.S. Scragg, M. Edoff, C. Platzer-Björkman, “Evolution of Na-S(-O) Compounds on the Cu2ZnSnS4 Absorber Surface and Their Effects on CdS Growth”, Presented at IEEE PVSC Portland, USA, 2016. (Poster)

J.K. Larsen, Y. Ren, N. Ross, E. Särhammer, S.-Y. Li, C. Platzer-Björkman, “Air annealing of Cu2ZnSnS4 in comparison to Cu2ZnSn(S,Se)4 absorbers”, Presented at EMRS, Lille, France, 2016 (Oral)

S. van Duren, Y. Ren, J. Scragg, J. Just, T. Unold, “Temperature dependent Raman scattering of CuS, ZnS, SnxSy, CuxSnSy and Cu2ZnSnS4 for in-situ process control”, Presented at EUPVSEC, Hambourg, Germany, 2015. (Poster)