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Joseph Razzell Hollis

Photo of Joseph Razzell Hollis


4800 Oak Grove Drive
M/S 183-301
Pasadena, CA 91109





Curriculum Vitae:

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Member of:

Astrobiology and Ocean Worlds


Joseph (also known as Joby) is a postdoctoral scholar in the planetary sciences section at JPL, where he works on the SHERLOC instrument going to Mars aboard the Mars 2020 rover. SHERLOC is an arm-mounted deep-ultraviolet Raman & fluorescence spectrometer, designed to detect the chemical signatures of past life or previous habitability on the red planet.

Joby is using his experience in optical spectroscopy to develop more advanced analytical methods for data collected by SHERLOC. This information will help us understand how to identify organic compounds on Mars, even at low concentrations, and determine whether or not they may have been produced by living organisms.

Joby also advocates for greater inclusivity and diversity for under-represented groups in STEM, particularly LGBT+ people, and is a trustee for the Pride in STEM charitable trust in the UK.


  • Ph.D. Physics, Imperial College London, UK, 2016.
  • M.Res. Plastic Electronics, Imperial College London, UK, 2012.
  • M.Chem. Chemistry, Sussex University, UK, 2011.

Professional Experience

  • 2020-present: JPL postdoctoral scholar
  • 2018-2020: NASA postdoctoral fellow

Community Service

  • Trustee of Pride in STEM, a UK-based charity with the goal of promoting visibility of LGBT+ people in science, technology, engineering and mathematics, while encouraging greater inclusivity of both minority gender and sexual identities by scientific organizations.
  • Co-organizer of Out Thinkers, a regular event that aims to celebrate and promote LGBT+ scientists by giving them the opportunity to talk about their work.
  • Runs the LGBT+ Physics twitter group.

Research Interests

Ultraviolet/visible wavelength Raman and fluorescence spectroscopy of complex organic molecules for detection of past life on Mars and other planetary surfaces.

Selected Publications

  1. Razzell Hollis, S. Ireland, W. Abbey, R. Bhartia, and L. W. Beegle, Deep-Ultraviolet Raman Spectra of Mars-Relevant Evaporite Minerals under 248.6 nm Excitation”, submitted Feb 2020
  2. V. Fox, R. Kupper, B. Ehlmann, J. Catalano, J. Razzell-Hollis, W. J. Abbey, D. Schild, R. Nickerson, and J. Peters, “Synthesis and characterization of Fe(III)-Fe(II)-Mg-Al smectite solid solutions and implications for planetary science”, submitted Jan 2020
  3. P. E. Martin, B. Ehlmann, N. H. Thomas, R. C. Wiens, J. Razzell Hollis, L. W. Beegle, R. Bhartia, S. M. Clegg, and D. L. Bailey, “Studies of a Lacustrine-Volcanic Mars Analog Field Site with Mars-2020-like Instruments”, Earth & Space Science, accepted Jan 2020
  4. J. azzell Hollis, D. Rheingold, R. Bhartia, and L. W. Beegle (2020) “An Optical Model for Quantitative DUV Raman Spectroscopy on Earth and Mars”, Appl. Spectrosc., in press, DOI: 10.1177/0003702819895299
  5. H. Sapers, J. Razzell Hollis, R. Bhartia, L. W. Beegle, V. J. Orphan, and J. P. Amend, “The cell and the sum of its parts: patterns of complexity in biosignatures as revealed by deep UV Raman spectroscopy”, Frontiers in Microbiology, 2019, 10, 679. DOI: 10.1063/1.4803912.
  6. S. Wood, J. Razzell Hollis, and J.-S. Kim; “Raman spectroscopy as an advanced structural nanoprobe for conjugated molecular semiconductors” J Phys. D: Appl. Phys, 2017, 50 (7), 73001. DOI: 10.1021/acs.jpcc.6b02898
  7. J. Razzell Hollis, F. D. Fleischli, A. A. Jahnke, N. Stingelin, D. S. Seferos, and J.-S. Kim, “Effects of Side-Chain Length and Shape on Polytellurophene Molecular Order and Blend Morphology” J. Phys. Chem. C, 2016, 121 (4), 2088-2098. DOI: 10.1021/acs.jpcc.6b11675
  8. J. Razzell-Hollis, Q. Thiburce, W. C. Tsoi, and J.-S. Kim, “Interfacial Chemical Composition and Molecular Order in Organic Photovoltaic Blend Thin Films Probed by Surface- Enhanced Raman Spectroscopy” ACS Appl. Mater. Interfaces, 2016, 8 (45), 31469–31481. DOI: 10.1021/acsami.6b12124
  9. J. Razzell-Hollis, S. Limbu, and J.-S. Kim, “Spectroscopic Investigations of Three-Phase Morphology Evolution in Polymer: Fullerene Solar Cell Blends” J. Phys. Chem. C, 2016, 120, 10806–10814. DOI: 10.1021/acs.jpcc.6b02898
  10. C. Hellmann, N. D. Treat, A. D. Scaccabarozzi, J. Razzell Hollis, F. D. Fleischli, J. H. Bannock, J. de Mello, J. J. Michels, J.-S. Kim, and N. Stingelin, “Solution processing of polymer semiconductor: Insulator blends-Tailored optical properties through liquid- liquid phase separation control” J. Polym. Sci. Part B Polym. Phys., 2015, 53, 304–310. DOI: 10.1002/polb.23656
  11. J. Razzell-Hollis, J. Wade, W. C. Tsoi, Y. Soon, J. Durrant, and J.-S. Kim, “Photochemical stability of high efficiency PTB7:PC70BM solar cell blends” J. Mater. Chem. A, 2014, 2, 20189–20195. DOI: 10.1039/c4ta05641h
  12. W. C. Tsoi, W. Zhang, J. Razzell Hollis, M. Suh, M. Heeney, I. McCulloch, and J.-S. Kim, “In- situ monitoring of molecular vibrations of two organic semiconductors in photovoltaic blends and their impact on thin film morphology” Appl. Phys. Lett., 2013, 102, 173302. DOI: 10.1039/c3tc31245c
  13. J. Razzell-Hollis, W. C. Tsoi, and J.-S. Kim, “Directly probing the molecular order of conjugated polymer in OPV blends induced by different film thicknesses, substrates and additives” J. Mater. Chem. C, 2013, 1, 6235–6243. DOI: 10.1063/1.4803912



Mars 2020