Congratulations Rajesh!!! Fourth Dr. from the group
OUR LATEST RESEARCH
Novel heterostructures with enhanced nonlinear optical response
The nonlinear optical absorbance of conventional materials is very weak, yet its magnitude dominates device performance in, for example, optical limiting and pulse shaping. Therefore, achieving a strong nonlinear optical response is a longstanding goal. We propose charge transfer between donor and acceptor materials as a means to greatly enhance nonlinear response, toward the realization of high-performance optical limiters. Excellent agreement between experiment and theory for a test hybrid material validates the idea, and guides the design and fabrication of an actual liquid-cell-based absorptive optical limiter, which outperforms benchmark devices.
[R. Yadav et. al., Phys. Rev. Applied 9, 044043 (2018)]
Exciton many body interactions in colloidal perovskite nanocrystals
Exciton many body interactions is the fundamental light–matter interaction which determines the optical response of the new class of colloidal perovskite nanocrystals of the general formula CsPbX3 [X = Cl or Br or I]. However, the understanding of exciton many body interactions manifested through the transient bi-excitonic Stark effect at the early time scales and the Auger recombination process in this new class of materials still remain rather incomplete. We are focussing on the many body exciton interactions under controlled conditions through ultrafast transient absorption spectroscopy. A large bi-excitonic redshift ∼30 meV to the effect of hot excitations on the excitonic resonance is observed at the early timescales. Fluence dependent studies show two-fold degenerate band edges. This explicit experimental evidence for the exciton many-body interactions in CsPbBr3 nanocrystals provides a powerful tool to explore the development of their prospective applications in light emitting devices, lasers, and solar cells.
[Aneesh J. et. al., J. Phys. Chem. C, 121 4734 (2017) ]