8th February 2021
Linear and nonlinear optical probing of various excitons in 2D inorganic-organic hybrid structures
Multiphoton excitation spectroscopy/imaging is one type of nonlinear optical process, which surpasses the disadvantages with conventional one-photon (typically in UV light) excitation. One-photon absorption due to its high absorption coefficient results into small penetration depths, therefore conventional photoluminescence (1PA-PL) spectroscopy and imaging provides information only from near surface regions and is influenced by many unwanted effects such as background emission and photo bleaching. Infrared excited two-photon induced photoluminescence (2PA-PL) and imaging possesses larger penetration depth and has emerged as an important nonlinear optical detection technique, finding applications such as single molecule/nanoparticle detection and multi-photon high contrast imaging. Here we present the study of highly intense infrared ultrashort pulses probing deep into some 2D layered Inorganic-Organic hybrid multiple Quantum wells and reveal several underlying structural perturbations (inter-layer distortions, intra-layer crumpling) and provide information about new excited states and their relaxation.
Prof. G. Vijaya Prakash, Mohammad Adnan and JJ. Baumberg
Department of Physics