Journal ArticleDOI
Coexistence of strongly and weakly confined energy levels in (Cd,Zn)Se quantum dots: Tailoring the near-band-edge and defect-levels for white light emission
TLDR
In this article, the white light emission from (Cd,Zn)Se system, which is a composite of Zn alloyed CdSe quantum dot and ZnSe-amorphous phase, was demonstrated.Abstract:
We demonstrate white light emission (WLE) from (Cd,Zn)Se system, which is a composite of Zn alloyed CdSe quantum dot and ZnSe-amorphous (ZnSe-a) phase. Detailed structural and photoluminescence emission studies on pure CdSe and (Cd,Zn)Se show cubic zinc blende structure in the size range of 2.5 to 5 nm. (Cd,Zn)Se quantum dots (QDs) also have a significant fraction of ZnSe-a phase. The near-band-edge green-emission in crystalline CdSe and (Cd,Zn)Se is tunable between 500 to 600 nm. The (Cd,Zn)Se system also exhibits a broad, deep defect level (DL) red-emission in the range 600 to 750 nm and a sharp ZnSe near-band-edge blue-emission (ZS-NBE) between 445 to 465 nm. While DL and CdSe near-band-edge (CS-NBE) emissions significantly shift with the size of QD due to strong confinement effect, the ZS-NBE show minimal change in peak position indicating a weak confinement effect. The intensities of ZS-NBE and DL emissions also exhibit a strong dependence on the QD size. A gamut of emission colors is obtained by com...read more
Citations
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Whispering Gallery Mode Assisted Enhancement in the Power Conversion Efficiency of DSSC and QDSSC Devices Using TiO2 Microsphere Photoanodes
TL;DR: In this paper, a composite comprising a TiO2 mesoporous microsphere with smooth surface (SμS-TiO2) exhibiting whispering gallery modes (WGM) and a commercial TiO 2 nanoparticle (Degussa P25) with an optimum ratio (80:20 wt %) showed significant enhancement in photoconversion efficiency (PCE) of DSSC and QDSSC devices.
Journal ArticleDOI
Whispering Gallery Mode Enabled Efficiency Enhancement: Defect and Size Controlled CdSe Quantum Dot Sensitized Whisperonic Solar Cells
TL;DR: The reported efficiency of QDSWSC is the highest compared to other CdSe based QDSSC made using TiO2 photoanode and I−/I3− liquid electrolyte and the concept of using whispering gallery for enhanced scattering is very promising for sensitized whisperonic solar cells.
Journal ArticleDOI
Band gap tailoring and photoluminescence performance of CdS quantum dots for white LED applications: influence of Ba2+ and Zn2+ ions
TL;DR: In this article, Ba2+ and Zn2+ ions are incorporated in the Cadmium sulfide (CdS) crystal structure without changing the original structure and the particle size was increased slightly as a function of Ba 2+ concentration and the reason for this change was ascertained to the change in ionic radius of the Ba 2 wt.
Journal ArticleDOI
Visualizing Heterogeneity of Monodisperse CdSe Nanocrystals by Their Assembly into Three-Dimensional Supercrystals.
Elena V. Shevchenko,Paul Podsiadlo,Paul Podsiadlo,Xiaohua Wu,Byeongdu Lee,Tijana Rajh,Rachel M. Morin,Matthew Pelton,Matthew Pelton +8 more
TL;DR: It is shown that the self-assembly of monodisperse CdSe nanocrystals synthesized at lower temperature into three-dimensional supercrystals results in the formation of separate regions within the supercrystal that display photoluminescence at two distinctly different wavelengths.
Journal ArticleDOI
State filling effects on photoluminescence and photovoltaic characteristic of aluminium-doped CdTe colloidal quantum dots stabilized in aqueous medium
Vijayaraj Venkatachalam,Sasikala Ganapathy,Ilaiyaraja Perumal,Santhanapanneer Devendrapandi,Arivarasan Ayyaswamy +4 more
TL;DR: In this article, the size shrinkages of CdTe and aluminium-doped Cdte (Al:CdTe QDs) colloidal quantum dots (QDs) were obtained by collecting the samples at different refluxing time.
References
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Journal ArticleDOI
Synthesis and characterization of nearly monodisperse CdE (E = sulfur, selenium, tellurium) semiconductor nanocrystallites
TL;DR: In this paper, a simple route to the production of high-quality CdE (E=S, Se, Te) semiconductor nanocrystallites is presented, based on pyrolysis of organometallic reagents by injection into a hot coordinating solvent.
Journal ArticleDOI
Light-emitting diodes made from cadmium selenide nanocrystals and a semiconducting polymer
TL;DR: In this article, a hybrid organic/inorganic electroluminescent device was constructed based on the recombination of holes injected into a layer of semiconducting p-paraphenylene vinylene (PPV) with electrons injected into the multilayer film of cadmium selenide nanocrystals.
Journal Article
Light-emitting diodes made from cadmium selenide nanocrystals and a semiconducting polymer
TL;DR: In this article, a hybrid organic/inorganic electroluminescent device was constructed based on the recombination of holes injected into a layer of semiconducting p-paraphenylene vinylene (PPV) with electrons injected into the multilayer film of cadmium selenide nanocrystals.
Journal ArticleDOI
Electronic wave functions in semiconductor clusters: experiment and theory
Journal ArticleDOI
Emergence of colloidal quantum-dot light-emitting technologies
TL;DR: In this paper, the authors summarized the key advantages of using quantum dots as luminophores in light-emitting devices (LEDs) and outlined the operating mechanisms of four types of QD-LEDs.