Substrate and Excitation Intensity Dependence of Saturable Absorption in Perovskite Quantum Dot Films

Mithun Bhowmick; Bruno Ullrich; Madeline Murchland; Xuan Zhou; Chari Ramkumar

doi:10.3390/nano13050871

Substrate and Excitation Intensity Dependence of Saturable Absorption in Perovskite Quantum Dot Films

Nanomaterials (Basel). 2023 Feb 26;13(5):871. doi: 10.3390/nano13050871.

Authors

Mithun Bhowmick¹, Bruno Ullrich², Madeline Murchland³, Xuan Zhou⁴, Chari Ramkumar⁵

Affiliations

¹ Department of Mathematical and Physical Sciences, Miami University, 4200 N University Blvd., Middletown, OH 45042, USA.
² Ullrich Photonics LLC, Manistique, MI 49854, USA.
³ Department of Geology and Environmental Science, Miami University, 250 S Patterson Ave., Oxford, OH 45056, USA.
⁴ Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
⁵ Department of Physics, Geology & Engineering Technology, Northern Kentucky University, Nunn Drive, Highland Heights, KY 41099, USA.

Abstract

Saturable absorption in perovskite quantum dot (PQD) films, leading to saturation in photoluminescence (PL), is reported. PL of drop-casting films was used to probe how excitation intensity and host-substrate influence the growth of PL intensity. The PQD films were deposited on single-crystal GaAs, InP, Si wafers and glass. Saturable absorption was confirmed through PL saturation in all films, with different excitation intensity thresholds, suggesting strong substrate-dependent optical properties, resulting from absorption nonlinearities in the system. The observations extend our former studies (Appl. Phys. Lett., 2021, 119, 19, 192103), wherein we pointed out that the PL saturation in QDs can be used to create all-optical switches in combination with a bulk semiconductor host.

Keywords: perovskite; photoluminescence; quantum dot; saturable absorber.

Grants and funding

Mithun Bhowmick is thankful for the CFR grant (2020) and the PREP funding from Office of Re-search and Innovation as well as Miami University Regionals Research grants for partially sup-porting the experiments presented here. Chari Ramkumar is thankful to the Department of Physics, Geology and Engineering Technology for partially supporting this publication.