About Us > Faculty & Staff > Faculty > Harry Efstathiadis

Associate Professor of Nanoengineering

Professional Background:

• Ph.D. (Experimental Condensed-Matter Physics) 1997, City University of New York
• M.S. (Physics) 1991, City College of New York

Areas of Research:

• Photovoltaics (CuInGaSe2 (CIGS), CuInGaS2, a-Si, and nc-Si)
• Quantum wells (SiC/Si and SiGe/Si)
• Thermoelectric devices
• Thin film deposition and characterization

Research description:

Professor Efstathiadis' research is focused on the following areas:

Thin-film solar cells
CIGS
This project includes the development of chemical (using CIGS nanoparticles) and sputter (bi-layer, co-sputtering) deposition processes for the absorber layer, low-cost methods for selenization and sulfurization, and studies of flexible substrates, barrier, and alternative to CdS buffer layers. The project also involves PV device fabrication and testing.

a-Si and nc-Si
This project is focused on process development for thin-film a-Si and nc-Si by evaporation and high frequency plasma enhanced CVD and anti-reflection and passivation coatings, front contact metallization for PV devices.

Quantum well thermoelectrics
This project is focused on the use of nanotechnology to engineer materials and structures such SiC/Si and SiGe/Si quantum wells with enhanced thermoelectric performance for applications such as chip and circuit board cooling and waste-heat recovery for power generation.

Thin film deposition and characterization
Low pressure thermal and plasma enhanced chemical vapor film depositions of carbon based alloys for hard coating and antireflective coatings for IR-windows.

Awards:

Materials Research Society - Finalist at the MRS Entrepreneurship Challenge, San Francisco, CA (2006).

Publications:

Z. Zhao, R. Teki, H. Efstathiadis, P. Haldar, "Metal oxide buffer layer for improving performance of polymer solar cell", Applied Surface Science 256 6053-6056 (2010).

D. Dwyer, R. Sun, H. Efstathiadis, and P. Haldar, "Characterization of Chemical Bath Deposited Buffer Layers for Thin Film Solar Cell Applications", Physica Status Solidi A, 1-7 (2010)

M. Mazumder, T. Borca-Tasciuc, S.Teehan, E. Stinzianni, H. Efstathiadis, and Slowa Solovyov, "Temperature dependent thermal conductivity of Si/SiC superlattice", Appl. Phys. Lett., 96 093103 (2010)

D. Dwyer, I. Repins, H. Efstathiadis, P. Haldar, "Selenization of Co-sputtered CuInAl Precursors", Solar Energy Materials & Solar Cells 94, 598-605 (2010)

Relationship of Aluminum Grain Size to the Grain Size of Polycrystalline Silicon Produced By the Aluminum-Induced Crystallization of Amorphous Silicon, E. Stinzianni, K. Dunn, H. Efstathiadis, and P. Haldar, IEEE, Photovoltaic specialists conference, Philadelphia, PA (2009)

Feasibility of Improving Front Metallization Lines for Photovoltaic Devices, A. Nguyen, H. Efstathiadis, A. Fioramonti, D. Morrissey, P. Haldar, IEEE, Photovoltaic specialists conference, Philadelphia, PA (2009)

Deposition of CuInAlSe2 films using co-sputtered precursors and selenization, D. Dwyer, I. Repins, H. Efstathiadis, P. Haldar, IEEE, Photovoltaic specialists conference, Philadelphia, PA (2009)

Two-dimensional Computer Modeling of Single Junction a-Si:H Solar Cells, C. Lee, H. Efstathiadis, J. E. Raynolds, P. Haldar, IEEE, Photovoltaic specialists conference, Philadelphia, PA (2009)

Role of Temperature and Duration of the Crystallization Anneal in the Texture Development of YBCO Prepared by TFA-MOD, E. A. Stinzianni, H. Efstathiadis, K. A. Dunn, and P. Haldar, Applied Superconductivity, IEEE Transactions on, (2009)

Deposition of Large Area, Directly Textured, ZnO:Al Films by Reactive-Environment, Hollow Cathode Sputtering", M. Patel, S. Guo, A. Stavrides, J. Cambridge, L. Le, H. Efstathiadis, P. Haldar, and A.E. Delahoy, Electronics, IEEE Transactions on, (2008)

Synthesis of Platinum Nanoparticles by Aerosol Assisted Deposition Method, O. Paschos, P. Choi, H. Efsthathiadis and P. Haldar, Thin Solid Films 516, 3796-3801, (2008)

Thickness Dependent Effects of Thermal Annealing and Solvent Vapor Treatment of Poly (3-hexylthiophene) and Fullerene Bulk Heterojunction Photovoltaics, L. Rice, Z. Zhao, H. Efstathiadis, P. Haldar, Mat. Res. Soc. Symp. Proc., Boston, MA (2008)

Silicon Power MOSFET at Low Temperatures: a Two-Dimensional Computer Simulation Study, H. Ye, C. Lee, J. Raynolds, H. Efstathiadis, P. Haldar, M. J. Hennessy and E. K. Mueller, Cryogenics, 215, 123-126, (2007)

Growth of textured MgO through e-beam evaporation and inclined substrate deposition, Y. Xu, C. H. Lei, B. Ma, H. Evans, H. Efstathiadis, M. Rane, M. Massey, U. Balachandran and R. Bhattacharya, Supercond. Sci. Technol. 19, 835-843 (2006)

Biaxially textured constantan alloy (Cu 55 wt%, Ni 44 wt%, Mn 1 wt%) substrates for YBa2Cu3O7-x coated conductors, C. V. Varanasi, L. Brunke, J. Burke, I. Maartense, N. Padmaja, H. Efstathiadis, A. Chaney and P. N. Barnes, Supercond. Sci. Technol. 19, 896-901, (2006)

Improving Performance of Cryogenic Power Electronics, P. Haldar, H. Ye, H. Efstathiadis, J. Raynolds, M. J. Hennessy, O. M. Mueller, and E. K. Mueller, Applied Superconductivity, IEEE Transactions on, 15, 2370-2375, (2005)

Fluorine Analysis and Microstructural Evolution in Coated YBCO Conductor Deposited by Metal Trifluoroacetate Process, M. V. Rane, H. Efstathiadis, H. Bakhru, M. W. Rupich, X. Li, W. Zhang, T. Kodenkandath, and P. Haldar, Applied Superconductivity, IEEE Transactions on, 16, (2005)

Synthesis and Spectroellipsometric Characterization of Y2O3-stabilized ZrO2-Au Nanocomposite Films for Smart Sensor Applications, G. Sirinakis, L. Sun, R. Siddique, H. Efstathiadis, M. A. Carpenter, and A. E. Kaloyeros, Mat. Res. Soc. Symp. Proc., 846, (2005)

Erbium-doped amorphous- Si-C-O matrix (a-SiCxOy:Er) - A novel silicon-based material for near-infrared optoelectronic applications, S. Gallis, M. Huang, V. Nikas, H. Efstathiadis, E. Eisenbraun, E. Nyein, Uwe Hommerich, and A. E. Kaloyeros, Mat. Res. Soc. Symp. Proc., 866, (2005)

"Numerical Thermal Simulation of Cryogenic Power Modules under Liquid Nitrogen Cooling," H. Ye, P. Haldar, and H. Efstathiadis, H., ASME Journal of Electronic Packaging, 15, (2005)

Silicon Power MOSFET at Low Temperatures: a Two-Dimensional Computer Simulation Study, H. Ye, C. W. Lee, J. Raynolds, H. Efstathiadis, P. Haldar, M. J. Hennessy, E. K. Mueller, ASME Journal of Electronic Packaging, 15, (2005)

Spectroellipsometric Characterization of Au-YSZ Nanocomposite Films, G. Sirinakis, R. Siddique, L. Sun, K. Dunn, H. Efstathiadis, M. A. Carpenter, and A. E. Kaloyeros, J. Mat. Res. (2005)

Carbon Nanotubes for Space Photovoltaic Applications, B. J. Landi, P. Denno, R. DiLeo, W. VanDerveer, R. Raffaelle, H. Efstathiadis, and P. Haldar, 19th Space Photovoltaics Research and Technology (SPRAT) conference proceedings on "Carbon Nanotubes for Space PV," (2005)

Photoluminescence and structural properties of Er-implanted amorphous SiCxOy thin films, S. Gallis, M. Huang, H. Efstathiadis, E. Eisenbraun, E. Nyein, U. Hommerich, and A. E. Kaloyeros, Appl. Phys. Lett., 87, 091901 (2005)

Long Length Textured MgO Template on Hastelloy by Ebeam Inclined Substrate Deposition in the Reel to Reel System, Y. Xu, C.H. Lei, B. Ma, B. Balachandran, H. Efstathiadis, H. Evans, M. Massey and R. Bhattacharya, Physica C (2005)

Optical Properties of Hafnium Oxide Films Grown by Laser Assisted Molecular Beam Deposition, L. Sun, J. Garvey, R. DeLeon, G. Tompa, R. Moore, and H. Efstathiadis, Mater. Res. Soc. Symp. Proc., 811 (2004)

Microstructural and compositional analysis of YBCO films grown by MOCVD before and after GCIB smoothing, M. Hatzistergos, H. Efstathiadis, J. Reeves, V. Selvamanickam, L. Allen, E. Lifshin, and P. Haldar, Physica C, 405, (2004)

Spectroscopic ellipsometry and grazing x-ray reflectrometry analyses on tungsten carbide films for diffusion barrier copper metallization schemes, L. Sun, J-C Fouere, T. Summet, M. Hatzistergos, and H. Efstathiadis, Thin Solid Films, 455-456, (2004)

Photoluminescence at 1540 nm from erbium-doped amorphous silicon carbide films, S. Gallis, H. Efstathiadis, M. Huang, E. Nyein, U. Hommerich, and A. E. Kaloyeros, J. Mat. Res., 19 (8), (2004)

Room-Temperature Photoluminescence at 1540 nm From Amorhous Silicon Carbide Films Implanted With Erbium, S. Gallis, H. Efstathiadis, M. Huang, A. E. Kaloyeros, E. Nyein, and U. Hommerich, Mater. Res. Soc. Symp. Proc. 815, (2004)

Investigation of Nanostructure-Polymer Blend Solar Cells, S. Huang, H. Efstathiadis, P. Haldar, H-G Lee, B. Landi and R. Raffaelle, International Energy Conversion Conference (IECEC) Proceedings, 12, (2004)

Fabrication of Nanorod Arrays for Organic Solar Cell Applications, S. Huang, H. Efstathiadis, and P. Haldar, H. -G. Lee, B. Landi, and R. Raffaelle, Mater. Res. Soc. Symp. Proc., 836, (2004)

Microstructural and electrical characterization of gas cluster ion beam smoothed YBCO films, M. Hatzistergos, H. Efstathiadis, E. Lifshin, A. Kaloyeros, J. Reeves and V. Selvamanickam, L. Allen and R. MacCrimmon, IEEE Applied Superconductivity transactions 13, 2470 (2003)

Thermal chemical vapor deposition of silicon carbide films as protective coatings for microfluidic structures, S. Gallis, U. Futschik, W. Sherwood, S. Hayes, C. G. Fountzoulas, J. Castracane, A. E. Kaloyeros, and H. Efstathiadis, Mat. Res. Soc. Symp. Proc., 742, (2003)

Laser Assisted Molecular Beam Deposition of Thin Films for Gate Dielectrics Applications, R. DeLeon, J. Garvey, G. Tompa, R. Moore and H. Efstathiadis, Mat. Res. Soc. Symp. Proc. 768, (2003)

Effect of Deposition Parameters on the Microstructural Evolution and Electrical Properties of Charge-Balanced Barium Strontium Titanate Ferroelectric Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition, C. Fountzoulas, S. Tidrow, M. Hatzistergos, and H. Efstathiadis, Mater. Res. Soc. Symp. Proc., 784 (2003)