Abstract
We, for the first time, report a temporal evolution of the electroluminescence (EL) intensity in lead sulfide (PbS) colloidal quantum dot (CQD) infrared light-emitting diodes. The EL intensity was varied during infrared light emission, and its origin is attributed to competition between the achievement of charge balance associated with interfacial charging at the PbS/ZnO CQD interface and the electric-field induced luminescence quenching. The effect of multi-carrier emission on the enhanced EL intensity is discussed relating to shifting in the wavelength at the peak EL intensity.
Highlights
Colloidal quantum dots (CQDs) have been assembled into a variety of devices, including light-emitting diodes (LEDs), solar cells, and biomedical sensors [1,2,3,4,5]
Excellent spectral tunability induced by quantum confinement effect associated with adjustable optical band gaps, simple solution process, and highly efficient photoluminescence (PL) quantum yields have motivated extensive research towards quantum dot light-emitting diodes (QLEDs), emerging as a next-generation display technology which can compete with organic light emitting diodes [5,6,7,8,9]
photoelectron spectroscopy in and air optical (PESA) characterizations, respectively, as seen in Figure 1c,d, which is consistent with the size molecular orbital (HOMO) energy level of 5.1 eV were determined from the optical absorption and determined from the transmission electron microscopy (TEM) image
Summary
Colloidal quantum dots (CQDs) have been assembled into a variety of devices, including light-emitting diodes (LEDs), solar cells, and biomedical sensors [1,2,3,4,5]. Understanding of the underlying mechanism for efficient emission has been one of the leading research themes, revealing that suppression of electric-field induced electrostatic interactions, including quantum dot (QD) charging and electric-field assisted exciton dissociation is crucial in reducing the external quantum efficiency (EQE) roll-off due to non-radiative loss, enabling integration of highly efficient QLEDs [10,11,12]. Emission layer, suppressing the non-radiative recombination process [13,14,15]. Charge injection in the QD emission layer can lead to an unbalanced charge state that causes the non-radiative Auger process. To reduce the surface states, core QDs were shelled by inorganic or organic layers, and a variety of surface ligand chemistries were applied for surface passivation [16,17,18]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
