Ultrafast Carrier Trapping in Thick-Shell Colloidal Quantum Dots
نویسندگان
چکیده
منابع مشابه
Ultrafast Charge Dynamics in Trap‐Free and Surface‐Trapping Colloidal Quantum Dots
Ultrafast transient absorption spectroscopy is used to study subnanosecond charge dynamics in CdTe colloidal quantum dots. After treatment with chloride ions, these can become free of surface traps that produce nonradiative recombination. A comparison between these dots and the same dots before treatment enables new insights into the effect of surface trapping on ultrafast charge dynamics. The ...
متن کاملSlow hot-carrier relaxation in colloidal graphene quantum dots.
Reducing hot-carrier relaxation rates is of great significance in overcoming energy loss that fundamentally limits the efficiency of solar energy utilization. Semiconductor quantum dots are expected to have much slower carrier cooling because the spacing between their discrete electronic levels is much larger than phonon energy. However, the slower carrier cooling is difficult to observe due to...
متن کاملCarrier relaxation dynamics in lead sulfide colloidal quantum dots.
We report transient absorption saturation measurements on lead sulfide colloidal nanocrystals at the first and second exciton energies and fit the results to a model incorporating intraband and interband relaxation processes. We study in detail the Auger recombination from the first excited state, which takes place when more than one electron-hole pair is excited in a dot. We find an Auger coef...
متن کاملUltrafast carrier dynamics in an InAs/InGaAs quantum dots-in-a-well heterostructure.
Ultrafast differential transmission spectroscopy is used to explore temperature-dependent carrier dynamics in an InAs/InGaAs quantum dots-in-a-well heterostructure. Electron-hole pairs are optically injected into the three dimensional GaAs barriers, after which we monitor carrier relaxation into the two dimensional InGaAs quantum wells and the zero dimensional InAs quantum dots by tuning the pr...
متن کاملPhotoluminescence upconversion in colloidal CdTe quantum dots
Efficient photoluminescence ~PL! up-conversion has been observed in colloidal CdTe quantum dots with an energy gain of as high as 360 meV. Compared with the normal PL, the peak energy of this up-converted PL ~UCPL! shows a redshift of about 80 meV, and the corresponding radiative lifetime becomes nearly twice as long. This UCPL is attributed to the carrier recombination involving surface states...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Journal of Physical Chemistry Letters
سال: 2017
ISSN: 1948-7185
DOI: 10.1021/acs.jpclett.7b01503