Damping of Cu-Associated Photoluminescence and Formation of Induced Absorption in Heavily Cu-Doped CdSe Quantum Dots

Abstract

We studied photoluminescence (PL) properties and nonlinear absorption characteristics of heavily Cu-doped CdSe colloidal quantum dots (QDs) under nanosecond laser pulse excitation. A strong dependence of basic exciton transition behavior and Cu dopant-associated PL on the concentration of copper ions and pump intensities was revealed for the first time. The saturation of the copper-associated PL signal was found to happen much faster than the saturation of nonlinear absorption. The induced absorption and saturation of high energy transitions due to the exciton−exciton interaction were investigated in Cu-doped CdSe QDs. The obtained results could be useful for the development of optoelectronic devices operating at room temperature on the basis of Cu-doped colloidal QDs.

Non-Markovian diffusion of excitons in layered perovskites and transition metal dichalcogenides

“…instead of spreading the phenomenon of focussing is observed. Also, if bt * { 1 this could happen at intermediate time scales for total MSD since then the displacement can be determined by free particles as it is shown from a comparison of eqn (19) and (20). Surely the exciton switches between the free and the trapped states, and MSD describes different sets of particles at different times.…”

“…They are formed when light interacts with a wide variety of systems. This includes inorganic and organic molecular semiconductors, [1][2][3] photosynthetic complexes, 4,5 polymers, [6][7][8] molecular aggregates, [9][10][11] semiconductor quantum wells and quantum wires, [12][13][14][15] colloidal quantum dots and nanoplatelets, [16][17][18][19][20][21][22][23][24][25] transition metal dichalcogenides, [26][27][28][29][30] and perovskites. [31][32][33][34][35][36][37] The dynamical properties of these systems are crucial for the advancement of optoelectronic applications including novel lasers, 16 photodetectors, 38 light-emitting diodes [39][40][41] and solar cells.…”

Mechanism of Enhancement of Stokes Shifted Photoluminescence Quantum Yield and Lifetime from Ag(I)-Doped CdSe Nanotetrapods: Implications for Optoelectronic and Photonic Devices

“…It has been reported that silica coating stabilizes NTPs, but a systematic investigation of the effect of such shelling on ϕ PL is yet to be performed . On a different note, only a few reports exist on transition-metal doping in NTPs, ,− but it is a popular strategy to enhance ϕ PL , excited-state lifetime and transportation time, as well as charge collection efficiency, which make them potential candidates for application in luminescent solar cells (LSCs) and light-emitting diodes (LEDs). − The key process, which is responsible for all these observations is the disruption of overlap between electron and hole wavefunctions, leading to a breakdown of electron–hole correlation, once the hole is captured by Ag in doped NCs . After hole capture by Ag, the hole wavefunction is localized only to the doped state, but the electron wavefunction is delocalized thoughtout the conduction band (CB) (Schemes B and S1).…”

Complex diffusion-based kinetics of photoluminescence in semiconductor nanoplatelets

“…17 Modern techniques of precise colloidal synthesis allow control of the shape, 18 size 19 and crystal structure of the nanocrystals. 20 Among these, there is a growing popularity of colloidal QDs and NPLs of CdSe with atomically defined thickness 5,21,22 and various shapes such as pure QDs and NPLs (core) as well as composite core-shell QDs and NPLs or core-crown NPLs. The composites are made of two different semiconductor materials, for instance, CdSe and CdS.…”