Chemistry and Biochemistry

Aziz Boulesbaa

Boulesbaa photo
Assistant Professor
(818) 677-2479
Office location:
CS 3313



PhD (Physical-Chemistry), Emory University & Temple University
MSc (Physics), Université Sorbonne Paris Cité (Paris 13)
BSc (Physics), Université des Sciences & de la Technologie Houari-Boumediane of Algiers


Oak Ridge National Laboratory




Materials Chemistry
Ultrafast Sciences: Nanomaterials for photovoltaic and biomedical applications

Our group uses various optical techniques to investigate ultrafast phenomena that take place in nanomaterials, biomolecules and their interfaces during brief times on the order of femtosecond time-scales (one millionth of one billionth of a second).  We incorporate a 5 W Ti:Sa femtosecond laser amplifier system to investigate ultrafast dynamics of electronic structures of nanomaterials and vibrational energy & coherence within chemical bonds.

  • Nanomaterials for photovoltaic applications: Due to their strong interaction with light, nanomaterials are good platform candidates for photovoltaic devices such as solar-cells and photodetectors.  The conversion efficiency of light into electricity in these devices relies on how efficiently excitons (bound electron-hole pairs) in the nanomaterial are photogenerated and then dissociated through charge transfer to an acceptor. Sometimes, the light absorbed by the nanomaterial is not fully consumed for the generation of “useful” excitons, but an important portion of energy is consumed as dissipated heat.  To understand this mechanism, we incorporate ultrafast spectroscopy to examine different nanomaterials, with a goal of overcoming this problem through designing and tailoring the chemical and physical structure of the nanomaterial.   To address the inefficiency of exciton dissociation (charge transfer), based on ultrafast spectroscopy investigations, we design hybrid nanomaterials (donor-acceptor composites) with the highest possible efficiency of charge transfer process.
  • Nanomaterials for biomedical applications: In the past, the employment of nanomaterials in the biomedical field was almost limited to drug delivery and bio labeling.  In recent years however, noble metal nanoparticles, such as gold, were used for photothermal therapy in cancer treatment.  This is due to their unique way of interacting with light that distinguishes them from other materials.  When the frequency of light matches that of the collective motion of electrons at the surface of a metal nanoparticle, the so-called localized surface plasmons resonance (LSPR) takes place, and consequently, the nanoparticle strongly absorbs photons with that frequency, which increases its temperature.  Clinically, the tumor area is injected with gold nanoparticles, followed by shining a laser with LSPR frequency to heat the nanoparticles, which burns and destroys the cancer cells.  In our Lab, we use ultrafast spectroscopy to track down the energy deposited through laser from absorption by the nanoparticle until its transfer to the biomolecule and the breaking of its chemical bonds.



  1. “Bromine Substitution Improves Excited-State Dynamics in Mesoporous Mixed Halide Perovskite Films”. E. M. Talbert, H. F. Zarick, A. Boulesbaa, N. Soetan, A. A. Puretzky, D. B. Geohegan, and R. Bardhan. Nanoscale, 9 (2017), 12005-12013.
  2. “Synthesis and Photoluminescence Properties of 2D Phenethylammonium Lead Bromide Perovskite Nanocrystals”. R. Guo, Z. Zhu, A. Boulesbaa, F. Hao, A. Puretzky, K. Xiao, J. Bao, Y. Yao, and W. Li. Small Methods, (2017), DOI: 10.1002/smtd.201700245
  3. “Ultrafast Excited-State Dynamics in Shape- and Composition- Controlled Gold-Silver Bimetallic Nanostructures”. H. F. Zarick, A. Boulesbaa, E. M. Talbert, A. Puretzky, D. Geohegan, and R. Bardhan. J. Phys. Chem. C, 121 (2017), 4540-4547.
  4. “Ultrafast Carrier Dynamics in Bimetallic Nanostructures-Enhanced Methylammonium Lead Bromide Perovskites”. H. F. Zarick, A. Boulesbaa, A. A. Puretzky, E. M. Talbert, D. B. Geohegan, R. Bardhan. Nanoscale, 9 (2017), 1475-1483.
  5. “Ultrafast Charge Transfer and Formation of Hybrid Excitons at 2D/0D Heterostructures”. A. Boulesbaa, K. Wang, M. Mahjouri-Samani, M. Tian, A. Puretzky, I. Ivanov, C. Rouleau, K. Xiao, B. Sumpter and D. Geohegan. J. Am. Chem. Soc., 138 (2016), 14713-14719.
  6. Capturing the Ultrafast Vibrational Decoherence of Hydrogen Bonding in Interfacial Water”. A. Boulesbaa, and E. Borguet. J. Phys. Chem. Lett., 7 (2016), 5080-5085.
  7. “Ultrafast Dynamics of Metal Plasmons Induced by 2D Semiconductor Excitons in Hybrid Nanostructure Arrays”. A. Boulesbaa, V. Babicheva, K. Wang, I. Kravchenko, M. W. Lin, M. Mahjouri-Samani, C. Jacobs, A. Puretzky, K. Xiao, I. Ivanov, C. Rouleau, and D. Geohegan. ACS Photonics, 3 (2016), 2389-2395.
  8. “In-plane Heterojunctions Enable Multiphasic 2D MoS2 Nanosheets as Efficient Photocatalysts for Hydrogen Evolution from Water Reduction”. R. Peng, L. Liang, Z. Hood, A. Boulesbaa, A. Puretzky, A. Ievlev, J. Come, O. Ovchinnikova, C. Ma, M. Chi, B. Sumpter, Z.Wu. ACS Catal.(2016), 6723–6729.
  9. “Tailoring Vacancies Far Beyond Intrinsic Levels Changes the Carrier Type in Monolayer MoSe2-x Crystals”. M. Mahjouri-Samani, L. Liang,A. Oyedele, M. Tian, N. Cross, M. W. Lin, A. Boulesbaa,C. M. Rouleau, A. Puretzky, K. Xiao, G. Eres, G. Duscher, B. G. Sumpter, and D. B. Geohegan. Nano Letters, 16 (2016), 5213-5220.
  10. “Interlayer Coupling in Twisted WSe2/WS2Bilayer Heterostructures Revealed by Optical Spectroscopy”. Wang, B. Huang, M. Tian, F. Ceballos, M. W. Lin, M. Mahjouri-Samani, A. Boulesbaa, A. Puretzky, C. Rouleau, M. Yoon, H.  Zhao, K. Xiao, G. Duscher, D. Geohegan. ACS Nano, 10 (2016), 6612-6622.
  11. “Improving Light Harvesting in Dye Sensitized Solar Cells using Hybrid Bimetallic Nanostructures”. H. F. Zarick, O. Hurd, A. Boulesbaa, W. R. Erwin, J. A. Webb, A. Puretzky, D. Geohegan,and R. Bardhan. ACS Photonics, 3 (2016), 385-394.
  12. “Observation of Two Distinct Negative Trions in Tungsten Disulfide Monolayers”. A. Boulesbaa, B. Huang, K. Wang, M. W. Lin, M. Mahjouri-Samani, C. Rouleau, K. Xiao, M. Yoon, B. Sumpter, A. Puretzky, and D. Geohegan. Phys. Rev. B 92, 115443 (2015).
  13. “Patterned Arrays of Lateral Heterojunctions within Monolayer 2D Semiconductors”. M. Mahjouri-Samani, M. W. Lin, K. Wang, A. Lupini, J. Lee, L. Basile, A. Boulesbaa, C. Rouleau, A. Puretzky, I. Ivanov, K. Xiao, M. Yoon , D. Geohegan. Nature Communications, (2015), DOI: 10.1038/ncomms8749.
  14. “Nonlinear Fano-Resonant Dielectric Metasurface”. Y. Yang, W. Wang, A. Boulesbaa, I. I. Kravchenko, D. P. Briggs, A. Puretzky, D. Geohegan, and J. Valentine. Nano Letters, 15 (2015), 7388-7393.
  15. “Nonlinear Conversion Using Fano-Resonant All-Dielectric Metasurfaces”. Y. Yang, A. Boulesbaa, I. Kravchenko, D. Briggs, A. Puretzky, D. Geohegan, J. G Valentine. Nonlinear Optics, NTu2B. 5 (2015).
  16. “Digital Transfer Growth of Patterned 2D Metal Chalcogenides by Confined Nanoparticle Evaporation”. M. Mahjouri-Samani, M. Tian, K. Wang, A. Boulesbaa, C. M. Rouleau, A. A. Puretzky, M. A. McGuire, B. R. Srijanto, K. Xiao, G. Eres, G. Duscher, and D. B. Geohegan. ACS Nano, 8 (2014), 11567-1175.
  17. “Seeing Is Believing: Hot Electron Based Gold Nanoplasmonic Optical Hydrogen Sensor”. D. Sil, K. GilRoy, A. Niaux, A. Boulesbaa, S. Neretina, and E. Borguet. ACS Nano, 8 (2014), 7755-7762.
  18. “Vibrational Dynamics of Interfacial Water by Free Induction Decay Sum-Frequency Generation (FID-SFG) at the Al2O3(1120)/H2O Interface”. A. Boulesbaa and E. Borguet. J. Phys. Chem. Lett., 5 (2014), 528-533.
  19. “Generation of Sub-30 fs Microjoule Mid-infrared Pulses for Ultrafast Vibrational Dynamics at Solid/Liquid Interfaces”. A. Boulesbaa, O. Isaienko, A. Tuladhar, and E. Borguet. Optics Letters, 38 (2013), 5008-5011.
  20. “Competition between Energy and Electron Transfer from CdSe QDs to Adsorbed Rhodamine B”. A. Boulesbaa, Z. Huang, D. Wu, and T. Lian. J. Phys. Chem. C, 114 (2010), 962-969.
  21. “Comparison of Electron Injection Dynamics from Rhodamine B to In2O3, SnO2, and ZnO Nanocrystalline Thin Films”. J. Huang, D. Stockwell, A. Boulesbaa, J. Guo, and T. Lian. J. Phys. Chem. C, 112 (2008), 5203 -5212.
  22. “Ultrafast Charge Separation at CdS Quantum Dot/Rhodamine B Molecule Interface”. A. Boulesbaa, A. Issac, D. Stockwell, Z. Huang, J. Huang, J. Guo, and T. Lian. J. Am. Chem. Soc., 129 (2007), 15132 -15133.