Rutile coupling prism for Micro- and Nano-Photonics - [e-mail]

Featured research:
Micro- and Nano-Photonics Group of Prof. Hans-Peter Wagner
Artificial semiconductor nanostructures as well as organic structures with dimensions down to nanometer size have attracted significant attention due to new device applications in photonics, optoelectronics and information technology. The next challenge in this research area is to fabricate and understand hybrid organic/ and plasmonic metal/organic/semiconductor nanostructures where various aspects of the optical and electrical properties may be controlled through active design of these materials.
In my research group we are designing and fabricating such artificial nanostructures and we are trying to better understand the coherent and incoherent relaxation dynamics of excited carriers and excitons in these structures with modern optical investigation methods. The result of our research is not only of fundamental physical interest but is of crucial importance for many potential optoelectronic applications including photovoltaics, lighting, holographic imaging and transformation optics. My research programs integrate teaching and research by providing training for graduate and undergraduate students in areas such as semiconductor physics, ultrafast optics, nanotechnology and information technology. This training will prepare students for a wide range of careers in research and development in corporate, government and university laboratories.

Publications:
H. P. Wagner, M. Kaveh, Q. Gao, H. Tan, C. Jagadish, W. Langbein, Population dynamics of excitons and electron-hole pairs in polytype wurtzite/zincblende InP nanowires, Phys. Rev. B 95, 045305, (2017).

M. Kaveh, Q. Gao, C. Jagadish, J. Ge, G. Duscher, and H. P. Wagner, Controlling the exciton emission of gold coated GaAs-AlGaAs core-shell nanowires with an organic spacer layer, Nanotechnology 27, 485204 (2016).

A. Dongol, J. Thompson, X. Wang, H. Schmitzer, D. Tierney and H. P. Wagner, Real-time contrast-enhanced holographic imaging using phase coherent photorefractive quantum wells, Optics Express 23, 12795 (2015).

M. Kaveh, O. Dyck, G. Duscher, Q. Gao, C. Jagadish, H. P. Wagner, Exciton emission from hybrid organic and plasmonic polytype InP nanowire heterostructures, Mater. Res. Express 2, 045001 (2015).

N. Wickremasinghe, J. Thompson, X. Wang, H. Schmitzer, H. P. Wagner, Controlling guided modes in organic waveguides with embedded metal films, J. Appl. Physics 117, 213102 (2015).

M. E. Sadat, Masoud Kaveh Baghbador, Andrew W. Dunn, H. P. Wagner, Rodney C. Ewing, Jiaming Zhang, Hong Xu, Giovanni M. Pauletti, David B. Mast, and Donglu Shi, Photoluminescence and photothermal effect of Fe3O4 nanoparticles for medical imaging and therapy, Appl. Phys. Lett. 105, 091903 (2014).

N. Wickremasinghe, X. Wang, H. Schmitzer, H. P. Wagner, Eliminating thermal effects in z-scan measurements of PTCDA films, Optics Express 22, 23955 (2014).

A. M. Ajward, X. Wang, N. Wickremasinghe, L. A. A. DeSilva, and H. P. Wagner, Radiative recombination of trapped excitons in Alq3 films: Importance of intermolecular interactions, Phys. Rev. B 88, 045205 (2013).

H. P. Wagner, H. Schmitzer, J. Lutti, P. Borri, W. Langbein, Effects of uniaxial pressure on polar whispering gallery modes in microspheres, J. Appl. Phys. 113, 243101 (2013).

A. Kabir, H. P. Wagner, Influence of electron density and trion formation on the phase-coherent photorefractive effect in ZnSe quantum wells, Phys. Rev. B 83, 125305 (2011).

A. Kabir, A. Dongol, X. Wang, H. P. Wagner, Real-time single-shot three-dimensional and contrast-enhanced optical coherence imaging using phase coherent photorefractive quantum wells, Appl. Phys. Lett., 97, 251116 (2010).

V. R. Gangilenka, L. V. Titova, L. M. Smith, H. P. Wagner, L. A. A. DeSilva, R. Scholz, Selective excitation of exciton transitions in PTCDA crystals and films, Phys. Rev. B 81, 155208 (2010).

A. Kabir, A. M. Ajward, H. P. Wagner, Holographic imaging using the phase coherent photorefractive effect in ZnSe quantum wells, Appl. Phys. Lett. 93, 063504 (2008).

H. Mu, D. Klotzkin, A. DeSilva, H. P. Wagner, D. White, B. Sharpton, Temperature dependence of electron mobility, electroluminescence and photoluminescence of Alq3 in OLED, J. Phys. D: Appl. Phys. 41, 235109, (2008).

V. R. Gangilenka, A. DeSilva, H. P.Wagner, R. E. Tallman, B. A. Weinstein, R. Scholz, Exciton Emission in PTCDA Thin Films under Uniaxial Pressure, Phys. Rev. B 77, 115206 (2008).

S. Tripathy and H. P. Wagner, A. Ueta and D. Hommel, Coherent Exciton-LO-Phonon Polarons in ZnSe Quantum Wells with Strong Confinement, Phys. Rev. B 75, 245316 (2007). Selected for the July 2007 issue of Virtual Journal of Ultrafast Science.

H. P. Wagner, A. DeSilva, V. R. Gangilenka, T. U. Kampen, Modified charge transfer emission in PTCDA/Alq3 layer structures, J. Appl. Phys. 99, 024501 (2006).