Semiconductor nanocrystals fabricated devices

Among the compound semiconductor materials, metal chalcogenide semiconductor nanocrystals have been extensively studied and widely used for linear and nonlinear optical devices and photovoltaic solar cells. The use of these materials as nanocrystals for large-scale fabrication of films with applications in solar energy conversion and other optoelectronic applications is an emerging and important area in materials science. Compared to the... 

Ramrakhiani [155] has reported the EL in nanocrystals and nanocomposites. Semiconductor nanocrystals exhibit many unique properties, which are promising for the improvement of electroluminescence (EL) devices. Combination of polymer and semiconductor nanocrystals allows the fabrication of flexible and lightweight EL devices. The incorporation of nanocrystals in polymer is expected to increase the life of the device and enhance the brightness of emission. The II-VI semiconductor nanoparticles and the nanocomposites in polymers have been synthesized by chemical route. The samples have been characterized and their electroluminescence has been investigated. 

Research on semiconductor nanoparticle technology by chemists, materials scientists, and physicists has already led to the fabrication of a number of devices. Initially, Alivisatos and co-workers developed an electroluminescence device from a dispersion of CdSe nanoparticles capped with a conducting polymer349 and then improved on this by replacing the polymer with a layer of CdS, producing a device with efficiency and lifetime increased by factors of 8 and 10, respectively. 0 Chemical synthetic methods for the assembly of nanocrystal composites, consisting of II-VI quantum dot polymer composite materials,351 represent one important step towards the fabrication of new functional devices that incorporate quantum dots. 

Preparing polymer nanocomposite OLED devices containing semiconductor NCs still remains a challenge. However, a few EL devices have been fabricated successfully [30-38]. For instance, Liu et al. investigated the properties of diode structures fabricated from PVK conducting polymer and luminescent Au-CdSe/ZnS core-shell nanocrystals. A series of double-layered EL devices with structures as represented in Fig. 3 were designed and fabricated [30]. 

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