Photo of S Ashok

S Ashok

Professor Emeritus


  • Engineering Science and Mechanics

407C Earth and Engineering Sciences Building


Interest Areas:

Semiconductor defect engineering, process-induced defects, hydrogen passivation, ion implementation, metal-semiconductor interfaces, and photovoltaics.






  • S Ashok, J. Chevallier, P. Kiesel and T. Ogino, 2007, Semiconductor Defect Engineering - Materials, Synthetic Structures and Devices II, Materials Research Society, pp. 369

Journal Articles

  • A. V. Vasin, Y. Y. Gomeniuk, A. V. Rusavsky, A. N. Nazarov, V. S. Lysenko, P. M. Lytvyn, O. G. Gontar, S. P. Starik, C. Nouveau and S Ashok, 2013, "Nano- and micro-scale morghological defects in oxidized a-SiC:H thin films", Phys. Stat. Sol. C, 10, pp. 619-623
  • Y. V. Gomeniuk, S. O. Gordienko*, A. N. Nazarov**, A. V. Vasin, A. V. Rusavskii, V. G. Stepanov, V. S. Lysenko, D. Ballutaud and S Ashok, 2012, "Effect of vacuum annealing on charge transport and trapping in a-Si1-xCx:H/c-Si heterostructures", J. Non-crystalline Solids, 358, pp. 168-173
  • S. O. Gordienko, A. N. Nazarov, A. V. Rusavsky, S Ashok, A. V. Vasin, Yu V. Gomeniuk and V. S. Lysenko, 2011, "Influence of oxidation temperature on photoluminescence and electrical properties of amorphous thin films SiC:H:O +Tb", Physica Status Solidi C, 8, pp. 2749-2751
  • Chandrasekaran Venkatasubramanian, Orlando M. Cabarcos, William R. Drawl, S. S. N. Bharadwaja, David L. Allara, S Ashok and Mark W. Horn, 2011, "Process - Structure - Property Correlations in Pulsed DC Reactive Magnetron Sputtered Vanadium Oxide Thin Films", J. Vac. Sci. Technol. A, 29, pp. 061504-1/7
  • K. Sarpatwari, S. E. Mohney, S Ashok and O. O. Awaldekarim, 2010, "Observation of Space Charge Limited Current in Re/4H-SiC Schottky Diodes", Physica, 207, (6), pp. 1509-1513
  • C. Venkatasubramanian, M. W. Horn and S Ashok, 2009, "Ion Implantation Studies on VOx Films Prepared by Pulsed DC Reactive Sputtering", Nucl. Instrum. Methods in Physics, B267, pp. 1476-1479
  • S. S. N. Bharadwaja, C. Venkatasubramanian, N. Fieldhouse, S Ashok, T. N. Jackson and M. W. Horn, 2009, "Low Temperature Charge Carrier Hopping Transport Mechanism in Vanadium Oxide Thin Films Grown using Pulse DC Sputtering", Appl. Phys. Lett., 94, pp. 222110-2
  • C. Venkatasubramanian, O. M. Cabarcos, D. L. Allara, M. W. Horn and S Ashok, 2009, "Correlation of Temperature Response and Structure of Annealed VOx Thin Films for IR Detector Applications", J. Vac. Sci. Technol., 27, pp. 956-961
  • C. Venkatasubramanian, M. Horn and S Ashok, 2008, "Annealing studies on VOx thin films prepared by pulsed dc reactive sputtering", J. Vac. Sci. Technol.
  • K. Sarpatwari, S. E. Mohney, S Ashok and O. Awaldekarim, 2008, "Observation of Space-charge Limited Currents in Re/ 4H-SiC Schottky Diodes", Semiconductor Sci. Technol.
  • El-Amine Kouadri-boudjelthia, Esidor Ntsoenzok, Roland Benoit, Gabrielle Regula, Hasnaa Etienne, Thomas Michel and S Ashok, , "Plasma Immersion Ion Implantation: a Pertinent Candidate for Low Cost Purification of mc-Si by Nanocavities", Nuclear Instruments and Methods in Physics Research
  • Mahmoud R M, Zhenyu Jiang, Jie Liu, Li Wang, S Ashok and Jian Xu, , "Modeling the spectral responsivity of ultraviolet GaN Schottky barrier photodetectors under reverse bias", J. Appl. Phys., 117

Conference Proceedings

  • J. Woolridge, E. Reutzel, S Ashok and L. Zou, 2012, "Laser-doped selective emitters for photovoltaic applications", SPIE Proceedings, 8549, pp. 6
  • H. E. Heinrichs, E. W. Reutzel, S Ashok and S. Mohney, 2012, "Parameter optimization of laser-doped selective emitters for applications in silicon solar cells", SPIE Proceedings(Laser Material Processing for Solar Energy), 8473, pp. 10
  • H. Assaf, E. Ntsoenzok, E. Leoni, M.-F. Barthe, M.-O. Rualt and S Ashok, 2007, "Anomalous Evolution of Bubbles and Gas Atoms in Kr-Implanted SiO2", Proc. Materials Research Society Spring Meeting, Materials Research Society, Pittsburgh, PA, 994, pp. 125-130
  • A. V. Vasin, A. A. Konchits, S. P. Kolesnik, A. V. Rusavsky, V. S. Lysenko, A. N. Nazarov, Y. Ishikawa and S Ashok, 2007, "Paramagnetic Defects and Photoluminescence in Carbon Rich a-SiC:H Films: Role of Hydrogen and Excess of Carbon", Proc. Materials Research Society Spring Meeting, Materials Research Society, Pittsburgh, PA, 994, pp. 321-326


  • S Ashok, 2013, "Schottky Barriers, Measurement, Modeling"
  • S. S. N. Bharadwaja, C. Venkatasubramanian, N. Fieldhouse, B. Gauntt, M. Y. Lee, S Ashok, E. C. Dickey, T. N. Jackson and M. Horn, 2010, "Processing Issues in Pulse DC Sputtering of Vanadium Oxide Thin Films for Uncooled Infrared Detectors", 221

Research Projects

Honors and Awards


Service to Penn State:

Service to External Organizations:




The Penn State Department of Engineering Science and Mechanics (ESM) is an internationally distinguished department that is recognized for its globally competitive excellence in engineering and scientific accomplishments, research, and educational leadership.

Our Engineering Science program is the official undergraduate honors program of the College of Engineering, attracting the University’s brightest engineering students. We also offer graduate degrees in ESM, engineering mechanics, engineering at the nano-scale, and an integrated undergraduate/graduate program.

Department of Engineering Science and Mechanics

212 Earth and Engineering Sciences Building

The Pennsylvania State University

University Park, PA 16802

Phone: 814-865-4523