Abstract
Magic clusters have attracted significant interest to explore the dynamics of quantum dot (QD) nucleation and growth. At the same time, CdSe magic-sized QDs reveal broadband emission in the visible wavelength region, which advantageously offer simple integration of a single-type of nanomaterial and high color rendering ability for white light-emitting diodes (LEDs). Here, we optimized the quantum yield of magic-sized CdSe QDs up to 22% via controlling the synthesis parameters without any shelling or post-treatment process and integrated them in liquid-state on blue LED to prevent the efficiency drop due to host-material effect. The fabricated white LEDs showed color-rendering index and luminous efficiency up to 89 and 11.7 lm/W, respectively.
Highlights
Quantum dots (QDs) are formed with an evolution from molecules to crystalline nanosolids[1,2]
To prevent a possible decay of the QD efficiency in device architecture due to host material effect, we hybridized QDs in liquid-state on blue light-emitting diodes (LEDs) die that led to a white LED with a color rendering index up to 89 and a luminous efficiency of ~10 lm/W at a high current injection level of 0.1 A, which was higher than the previous studies (Table 1)
To achieve efficient and broad photoluminescence spectrum, which covers the entire visible region, we optimized radiative surface trap-states of CdSe QDs to find the point with highest quantum yield
Summary
Quantum dots (QDs) are formed with an evolution from molecules to crystalline nanosolids[1,2]. The trap-states of the magic-sized QDs show broadband surface-state emission, which covers the entire visible region and can be used for light-emitting diodes (LEDs)[17,18,19] They have benefitted a simple core structure with the integration of only one type of QDs comparing to the other traditional QD-based white LEDs, which use two or more types of QD layers[20,21]. Different from the previous studies, we maximized the quantum yield of white-emitting CdSe QDs by controlling the synthesis parameters of reaction time and temperature, and their quantum yields reached up to 22% without shell formation or post treatment process for white LEDs. To prevent a possible decay of the QD efficiency in device architecture due to host material effect, we hybridized QDs in liquid-state on blue LED die that led to a white LED with a color rendering index up to 89 and a luminous efficiency of ~10 lm/W at a high current injection level of 0.1 A, which was higher than the previous studies (Table 1)
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
