Showing papers by "Cao Weiran published in 2013"
TL;DR: It is shown that treating the polymer:nanocrystal hybrid film in an ethanedithiol-containing acetonitrile solution can increase the efficiency of the hybrid PV devices by 30-90%, and a maximum power conversion efficiency of 5.2 ± 0.3% was obtained in the PCPDTBT:CdSe devices.
Abstract: Advances in colloidal inorganic nanocrystal synthesis and processing have led to the demonstration of organic–inorganic hybrid photovoltaic (PV) cells using low-cost solution processes from blends of conjugated polymer and colloidal nanocrystals. However, the performance of such hybrid PV cells has been limited due to the lack of control at the complex interfaces between the organic and inorganic hybrid active materials. Here we show that the efficiency of hybrid PV devices can be significantly enhanced by engineering the polymer–nanocrystal interface with proper chemical treatment. Using two different conjugated polymers, poly(3-hexylthiophene) (P3HT) and poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT), we show that treating the polymer:nanocrystal hybrid film in an ethanedithiol-containing acetonitrile solution can increase the efficiency of the hybrid PV devices by 30–90%, and a maximum power conversion efficiency of 5.2 ± 0.3% was ob...
113 citations
Patent•
26 Sep 2013TL;DR: In this paper, a dielectric/metal/dielectric layered structure of QD-LEDs is described, where the first layer comprises metal oxide nanoparticles or polymer-nanoparticle blends and is 10 to 40 nm in thickness.
Abstract: Quantum dot light emitting diodes (QD-LEDs) are formed that are transparent and emit light from the top and bottom faces. At least one electrode of the QD-LEDs is a dielectric/metal/dielectric layered structure, where the first dielectric comprises metal oxide nanoparticles or polymer-nanoparticle blends and is 10 to 40 nm in thickness, the metal layer is 5 to 25 nm in thickness, and the second dielectric layer is a nanoparticulate, polymer-nanoparticle blend or continuous layer of 30 to 200 nm in thickness and is situated distal to the light emitting layer of the QD-LED.
27 citations
TL;DR: In this article, the light out-coupling efficiency of organic light-emitting devices was enhanced using microlens arrays fabricated by a direct printing technique, and the high surface-free energy of a glass substrate was modified through the use of a hydrophobic silane coupling agent thus achieving a high contact angle for liquid droplets.
Abstract: The light out-coupling efficiency of organic light-emitting devices was enhanced using microlens arrays fabricated by a direct printing technique. The high surface-free energy of a glass substrate was modified through the use of a hydrophobic silane coupling agent thus achieving a high contact angle for liquid droplets. A transparent monomer mixture of multifunctional thiol and ene was employed as a lens material. The light out-coupling efficiency was improved by 30% using printed microlens arrays without altering the electroluminescent spectrum.
15 citations
01 Jun 2013
TL;DR: In this article, Colloidal quantum-dot based hybrid light-emitting diodes (QD-LEDs) that exhibit high efficiency, long lifetime, solution processability, color tunability and narrow emission bandwidth are reported.
Abstract: Colloidal quantum-dot based hybrid light-emitting diodes (QD-LEDs) that exhibit high efficiency, long lifetime, solution processability, color tunability and narrow emission bandwidth are reported. The devices possess maximum current and power efficiency of 3.2 cd/A and 2.1 lm/W for blue, 60 cd/A and 54 lm/W for green, and 15 cd/A and 18 lm/W for red emission. With exceptional good lifetime, the current QD-LEDs are promising for flat panel display applications.
2 citations
03 Nov 2013
TL;DR: In this article, a solution processed light-emitting devices using colloidal quantum dot as emitters was reported, achieving high efficiency and low voltage operation with the use of a polymer hole-transport layer and a ZnO nanoparticle electron transport layer.
Abstract: We report solution processed light-emitting devices using colloidal quantum dot as emitters. High efficiency and low voltage operation was achieved with the use of a polymer hole-transport layer and a ZnO nanoparticle electron-transport layer.
1 citations
16 Jun 2013
TL;DR: In this paper, the authors demonstrate a clear dependence of the growth and photovoltaic performance of zinc phthalocyanine (ZnPc) films on the presence of dual organic interlayers of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and tetracene on the transparent indium-tin oxide anode.
Abstract: We demonstrate a clear dependence of the growth and photovoltaic performance of zinc phthalocyanine (ZnPc) films on the presence of dual organic interlayers of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and tetracene on the transparent indium-tin oxide anode. The PEDOT:PSS layer enables the two-dimensional growth of tetracene, which in turn leads to enhanced molecular packing and exciton diffusion in the ZnPc film. Coupled with exciton blocking provided by tetracene, this results in a more than 100% increase in the external quantum efficiency for ZnPc absorption in bilayer ZnPc/C60 devices. The power conversion efficiency is increased from 2.0% to 3.5% for bilayer devices, and from 3.8% to 5.0% for the more efficient planar-mixed devices.
1 citations