Operating lifetime is the main problem that complicates the use of polymeric light-emitting diodes (LEDs). A class of electron transport (ET) polymers [poly(aryl acrylate) and poly(aryl ether)s] is reported in which moieties with high electron affinities are covalently attached to stable polymer backbones. Devices based on poly(p-phenylenevinylene) (PPV) prepared with these materials exhibited a 30-fold improvement in stability and, in one case, dramatically lower (10 volts versus about 30 volts) operating voltage relative to those having conventional ET layers. The current-carrying capacity of indium tin oxide-PPV-polymeric ET layer-aluminum LEDs was also increased by a factor of 30. These improvements lead to an enhancement in power efficiency of nearly an order of magnitude. Choosing polymers with high glass transition temperatures increases device lifetime.

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A dielectrophoretic, DEP, force induced assembly technique was used to achieve close-packed 2D colloidal photonic crystals on a substrate. The experimental tests were conducted on 5.3 μm carboxyl fictionalized polystyrene (PS) particles at a 6 AC Voltage and 1 MHz frequency. After the crystal was completely formed at the center of electrodes, a polyacrylamide solution was added to the system to immobilize the photonic crystals.

We have grown for the first time 3-8 nm CdSe and pseudomorophic Zn x Cd 1-x Se/Zn y Cd 1-y Se cladded quantum dots (CQDs) (x > y) in a novel Photo assisted Microwave Plasma Metalorganic Chemical Vapor Phase Deposition (PMP-MOCVD) reactor. Influence of growth parameters including microwave power, ultraviolet intensity, gas phase II/VI [Zn+Cd/Se] molar ratio, temperature of growth, and post-growth processing has been studied. High-resolution transmission electron microscopy (HR-TEM is used to compare the dots with colloidal dots reported in the literature. Simulation of the optical gain in an active layer hosting these dots is presented.