Photoemission of Energetic Hot Electrons Produced via Up-Conversion in Doped Quantum Dots

Nano Letters ◽  
2016 ◽  
Vol 16 (11) ◽  
pp. 7270-7275 ◽  
Author(s):  
Yitong Dong ◽  
David Parobek ◽  
Daniel Rossi ◽  
Dong Hee Son
Keyword(s):  
Quantum Dots ◽  
Hot Electrons ◽  
Doped Quantum Dots

Photons and charges from colloidal doped semiconductor quantum dots

2019 ◽  
Vol 7 (47) ◽  
pp. 14788-14797 ◽  
Author(s):  
Tian Qiao ◽  
David Parobek ◽  
Dong Hee Son
Keyword(s):  
Quantum Dots ◽  
Semiconductor Quantum Dots ◽  
Hot Electrons ◽  
Doped Quantum Dots

This work discusses the photophysical pathways in doped quantum dots responsible for generating photons of non-exciton origin and hot electrons.

scholarly journals Spin blockade and phonon bottleneck for hot electron relaxation observed in n-doped colloidal quantum dots

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Junhui Wang ◽  
Lifeng Wang ◽  
Shuwen Yu ◽  
Tao Ding ◽  
Dongmei Xiang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Phonon Scattering ◽  
Surface States ◽  
Hot Electrons ◽  
Hot Electron ◽  
Phonon Bottleneck ◽  
Spin Interactions ◽  
Doped Quantum Dots ◽  
Electron Relaxation ◽  
Spin Blockade

AbstractUnderstanding and manipulating hot electron dynamics in semiconductors may enable disruptive energy conversion schemes. Hot electrons in bulk semiconductors usually relax via electron-phonon scattering on a sub-picosecond timescale. Quantum-confined semiconductors such as quantum dots offer a unique platform to prolong hot electron lifetime through their size-tunable electronic structures. Here, we study hot electron relaxation in electron-doped (n-doped) colloidal CdSe quantum dots. For lightly-doped dots we observe a slow 1Pe hot electron relaxation (~10 picosecond) resulting from a Pauli spin blockade of the preoccupying 1Se electron. For heavily-doped dots, a large number of electrons residing in the surface states introduce picosecond Auger recombination which annihilates the valance band hole, allowing us to observe 300-picosecond-long hot electrons as a manifestation of a phonon bottleneck effect. This brings the hot electron energy loss rate to a level of sub-meV per picosecond from a usual level of 1 eV per picosecond. These results offer exciting opportunities of hot electron harvesting by exploiting carrier-carrier, carrier-phonon and spin-spin interactions in doped quantum dots.

Hot Electrons Generated from Doped Quantum Dots via Upconversion of Excitons to Hot Charge Carriers for Enhanced Photocatalysis

2015 ◽  
Vol 137 (16) ◽  
pp. 5549-5554 ◽  
Author(s):  
Yitong Dong ◽  
Julius Choi ◽  
Hae-Kwon Jeong ◽  
Dong Hee Son
Keyword(s):  
Quantum Dots ◽  
Charge Carriers ◽  
Hot Electrons ◽  
Doped Quantum Dots

Colloidal Transition-Metal-Doped Quantum Dots

2010 ◽  
pp. 397-453 ◽  
Author(s):  
R√©mi Beaulac ◽  
Stefan Ochsenbein ◽  
Daniel Gamelin
Keyword(s):  
Quantum Dots ◽  
Transition Metal ◽  
Doped Quantum Dots ◽  
Metal Doped

Electron Paramagnetic Resonance in Ge/Si Heterostructures with Mn-Doped Quantum Dots

JETP Letters ◽  
2019 ◽  
Vol 109 (4) ◽  
pp. 270-275
Author(s):  
A. F. Zinovieva ◽  
V. A. Zinovyev ◽  
N. P. Stepina ◽  
A. V. Katsuba ◽  
A. V. Dvurechenskii ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Paramagnetic Resonance ◽  
Paramagnetic Resonance ◽  
Doped Quantum Dots ◽  
Electron Paramagnetic ◽  
Mn Doped

scholarly journals Observation of a phonon bottleneck in copper-doped colloidal quantum dots

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Lifeng Wang ◽  
Zongwei Chen ◽  
Guijie Liang ◽  
Yulu Li ◽  
Runchen Lai ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cadmium Selenide ◽  
Phonon Scattering ◽  
Photochemical Reactions ◽  
Hot Electrons ◽  
Colloidal Quantum Dots ◽  
Hot Electron ◽  
Electron Cooling ◽  
Phonon Bottleneck ◽  
Cooling Mechanism

Abstract Hot electrons can dramatically improve the efficiency of solar cells and sensitize energetically-demanding photochemical reactions. Efficient hot electron devices have been hindered by sub-picosecond intraband cooling of hot electrons in typical semiconductors via electron-phonon scattering. Semiconductor quantum dots were predicted to exhibit a “phonon bottleneck” for hot electron relaxation as their quantum-confined electrons would couple very inefficiently to phonons. However, typical cadmium selenide dots still exhibit sub-picosecond hot electron cooling, bypassing the phonon bottleneck possibly via an Auger-like process whereby the excessive energy of the hot electron is transferred to the hole. Here we demonstrate this cooling mechanism can be suppressed in copper-doped cadmium selenide colloidal quantum dots due to femtosecond hole capturing by copper-dopants. As a result, we observe a lifetime of ~8.6 picosecond for 1Pe hot electrons which is more than 30-fold longer than that in same-sized, undoped dots (~0.25 picosecond).

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