EventDr. Talha Erdem

Colloidal nanomaterials for photonics: A research portfolio
on white LEDs, photonic crystals, smart self-assembly

Colloidal nanoparticles have a significant place in our lives, we encounter them everywhere from viruses to paints, from milks to televisions. The field of photonics is one of the many research branches where these particles are often employed for various purposes. Today, I will summarize my research efforts using colloidal particles in a broader perspective. I will start with discussing the importance of colloidal nanocrystals for white LED applications and summarize the necessary conditions for achieving high-quality lighting.1,2 Next, I will continue with our efforts on macrocrystals of nanocrystals to realize high-quality, efficient, and stable white LEDs.3,4 Subsequently, I will talk about the utilization of plasmonic and excitonic interactions in these macrocrystal to improve the emission capabilities of nanocrystals.5-7 Then, I will move from white LEDs to photonic crystals of colloids. These liquid crystals made of low refractive index particles enable transparency and tunable reflection in blue, green, and red colors over a broad angle. Next, I will talk about our work on suppressing the scattering features of raspberry particles that otherwise scatter very strongly and can form photonic crystals.   Finally, I will briefly present the utilization of DNA-driven self-assembly on controlling the optical properties of the assembled system.

  1. T. Erdem et al., Optics Express 18, 340 (2010).
  2. Erdem and H. V. Demir, Nanophotonics 2, 57-81 (2013).
  3. Adam and T. Erdem et al., ACS Appl. Mater. Inter. 7, 23364 (2015).
  4. Soran-Erdem and T. Erdem et al., ACS Nano 10, 5333 (2016).
  5. Erdem et al., Nano Research 8, 860-869 (2015).
  6. Soran-Erdem and T. Erdem et al., J. Phys. Chem. Lett. 6, 1767-1772 (2015).
  7. Erdem et al., Optics Express 24, A74 (2016).

About The Speaker


Dr. Talha Erdem received his B. Sc., M. Sc., and Ph. D. degrees all in Electrical and Electronics Engineering from Bilkent University in 2009, 2011, and 2016, respectively. During his M. Sc. and Ph. D. education, he worked on the development of efficient and high-quality white LEDs. He proposed a paradigm shift in designing white LEDs from using broadband emitters to using discrete color components having narrowband emission. Furthermore, he explored the possibilities to employ near-field interactions such as plasmonics and nonradiative energy transfer for increasing the efficiency of color converting LEDs. On account of his works, he was awarded the SPIE Scholarship in Optics and Photonics and IEEE Photonics Society Graduate Student Scholarship. In 2016, he was awarded the Newton International Fellowship by the Royal Society and moved to Cavendish Laboratory at the University of Cambridge to pursue his postdoctoral research. His current research focuses on the design of photonic systems by utilizing smart self-assembly techniques. In addition to his research, Dr. Erdem also serves in the editorial board of Royal Society Open Science journal.