**1. Introduction**

We are grateful to the authors and hope that the contribution of authors and number of participating countries with continue to grow, while optoelectronics itself will be the

Editor:

**Sergei L. Pyshkin**

Kishinev, Moldova

Clemson University South Carolina, USA

Co-editor:

**John M. Ballato** Professor, Director

Clemson University South Carolina, USA

Professor, Principal Investigator Institute of Applied Physics Academy of Sciences of Moldova

Adjunct-Professor, Senior Fellow

School of Engineering and Materials Science

Center for Optical Materials Science and Engineering Technologies

object in permanent demand to further enhance human quality of life.

X Preface

This Chapter contains our latest achievements on organic and inorganic light emitters for display and waveguide applications. Two simultaneous efforts are described and analyzed. The first is the application of some transparent polymers to photoactive device structures. The second area focuses on the fabrication of optoelectronically-important structures based on GaP nanoparticles and their composites. The choice of materials are further complemen‐ tary since they each are considered candidates for use in all optical circuits with commercial interest for light emitters, waveguides, converters, accumulators and other planar, fiber or discrete micro-optic elements.

Three objectives have been fulfilled and are reported here: 1) the development of new tech‐ nologies for the preparation of nanocrystalline composite and GaP films; 2) the fabrication of novel optical planar light emissive structures for light emissive devices based on GaP/poly‐ mers nanocomposites; and 3) the generalization of experimental results from light emissive GaP bulk crystals, nanoparticles and nanocomposites.

Photoluminescence (PL), Raman light scattering (RLS), X-ray diffraction (XRD), atomic force and transmission electron microcopies (AFM and TEM) and other diagnostic methods have been used to characterize quality of GaP bulk and nanocrystals, GaP/polymers nanocompo‐ sites and to evaluate emissive efficiency of the obtained device structures. New solutions based on growth technique with use of modern analytical techniques were applied for growth and monitoring of semiconducting and composite films and fibers.

One of the main results described in the present Chapter is the creation and investigation of nanocomposite films based on GaP nanoparticles inserted into optically transparent polymers to prepare unique light emissive devices for optoelectronic applications. Differ‐ ent polymers were tested that combine the processability and durability of engineering

thermoplastics with suitable for GaP nanoparticles optical, electrical, thermal, and envi‐ ronment resistant properties.

Ultrasonication and ultracentrifugation have been applied during the synthesis and selec‐

Advanced Light Emissive Device Structures http://dx.doi.org/10.5772/52416 3

The relevant spectra of photoluminescence and Raman light scattering, X-ray diffraction and electron microscopy of the nanoparticles prepared under different conditions have been compared with each other as well as with those from bulk single crystals. Thoroughly-pre‐ pared powders and suspensions of the nanoparticles have been used for preparation of GaP film nanocomposites on the base of different polymers compatible with the nanoparticles on

**2.1. Equipment for fabrication of nanoparticles, fluoropolymers and nanocomposites**

The equipment for fabrication of fluoropolymers and polymer nanocomposites has been ela‐ borated by the author (JB) from Clemson University during our joint activity on light emis‐ sive structures. This equipment and approaches were applied to our specific needs without

It was found the synthesis on the base of white phosphorus gives the best quality of GaP nano‐ particles. Due to the known prohibition for free sale of white phosphorus we have elaborated

The device is the silica tube, which is hermetic to the air, and is heated from one end while the P vapor is transferred by a neutral gas (nitrogen or argon) environment at the other cooled end of the tube where it is condensed there to form white phosphorus. After comple‐ tion of the process the white phosphorus can be removed; the tube must be immersed into a

The obtained white phosphorus must be stored as a water suspension. Then this suspen‐ sion by melting in boiled water is turned into the substance using in the synthesis of

A new model of autoclave for the hydrothermal synthesis of GaP nanoparticles from the ap‐ propriate chemical solutions has been established given the requisite high temperatures (up

the facilities for its preparation using sublimation of its red modification (see Figure 1).

tion of nanoparticles to increase their quality and to select them on dimensions.

optical and mechanical properties.

*2.1.1. Equipment for sublimation of phosphorus*

**Figure 1.** Preparation of white phosphorus.

GaP nanoparticles.

water bath that to avoid inflammation of phosphorus in air.

*2.1.2. Equipment for hydrothermal and colloidal synthesis*

any serious modification.

Perfect single crystals from our unique collection of pure and doped GaP single crystals [1-25] compared with GaP nanoparticles prepared by us [26-31] serve as a standard yielding funda‐ mental new knowledge and insights into semiconductor optical physics. Elaborating optimal methods of fabrication of GaP nanoparticles and their light emissive composites with compati‐ ble polymers [32-36] we use our own experience and literature data [37-39]. Due to considera‐ ble efforts in the past, including our contribution also, GaP has received significant attention as a material for use in a wide range of important modern optoelectronic devices including pho‐ todetectors, light emitters, electroluminescent displays and power diodes as well as being a model material with which to investigate the fundamental properties of semiconductors.

These two components of the composites, GaP and specially selected polymers, were unified based on their compatibility with the light emission spectral region as well as in their eventual integration into all optical circuits where bulk crystals or nanocrystals of GaP have been of commercial interest mainly for fiber and planar light emissive and micro-optic elements.

We hope our device structures obtained with application of accumulated for years results in their optics and technology [1-36, 41-43] will have significant commercial value because they present a new optical medium and product.
