2
Strategies for the Scalable Synthesis of
Quantum Dots and Related Nanodimensional
Materials
Paul O’Brien and N. Pickett
2.1
Introduction
At present there is a considerable interest in the potential for use of materials with
dimensions that are best defined in terms of nanometers; especially so-called
quantum dots as derived from bulk compound semiconducting materials [1–3]. To
date almost all work on the synthesis of quantum dots has been carried out in the
academic sector, with a strong emphasis on the synthesis of high quality material
in small quantity. One product containing quantum dots has to date been marketed, a biological probe formed by binding particles of CdSe to form Qdot
TM
streptavidin conjugates [4]. However, there is potentially a wide range of applications for such materials which means that the production of quantities of material
is becoming an issue of real interest.
The situation is analogous to the development of metal organic precursors for
the deposition of compound semiconductors by metal organic chemical vapour
deposition (MOCVD). These compounds underwent a period of intense research
and development in the last 20 years of the 20
th century [5]. Although work in this
area continues it now underpins a mature technology, although the deposition of
oxides is still undergoing active development. In its infancy this aspect of materials
chemistry was crucial in delivering new functional devices especially in optoelectronics (e.g. high performance solid-state lasers and LEDs) many of which are in
everyday use. It seems probable that the emergence of a materials chemistry for
the scalable manufacture of nanodimensional materials will be of similar importance in the first half of the present century.
This chapter will address issues concerned with the synthesis of quantum dots
in quantity. Many issues remain ill-defined in this area including the simple problem of defining what will form a proper specification for nanodimensional materials such as quantum dots. A typical material may involve two types of solid-state
compound and an apparently ever increasingly complex organic coat used to enhance the stability of the material and the solvents in which it can be dispersed/
processed. Again analogies with conventional semiconducting materials can be
12
Strategies for the Scalable Synthesis of
Quantum Dots and Related Nanodimensional
Materials
Paul O’Brien and N. Pickett
2.1
Introduction
At present there is a considerable interest in the potential for use of materials with
dimensions that are best defined in terms of nanometers; especially so-called
quantum dots as derived from bulk compound semiconducting materials [1–3]. To
date almost all work on the synthesis of quantum dots has been carried out in the
academic sector, with a strong emphasis on the synthesis of high quality material
in small quantity. One product containing quantum dots has to date been marketed, a biological probe formed by binding particles of CdSe to form Qdot
TM
streptavidin conjugates [4]. However, there is potentially a wide range of applications for such materials which means that the production of quantities of material
is becoming an issue of real interest.
The situation is analogous to the development of metal organic precursors for
the deposition of compound semiconductors by metal organic chemical vapour
deposition (MOCVD). These compounds underwent a period of intense research
and development in the last 20 years of the 20
th century [5]. Although work in this
area continues it now underpins a mature technology, although the deposition of
oxides is still undergoing active development. In its infancy this aspect of materials
chemistry was crucial in delivering new functional devices especially in optoelectronics (e.g. high performance solid-state lasers and LEDs) many of which are in
everyday use. It seems probable that the emergence of a materials chemistry for
the scalable manufacture of nanodimensional materials will be of similar importance in the first half of the present century.
This chapter will address issues concerned with the synthesis of quantum dots
in quantity. Many issues remain ill-defined in this area including the simple problem of defining what will form a proper specification for nanodimensional materials such as quantum dots. A typical material may involve two types of solid-state
compound and an apparently ever increasingly complex organic coat used to enhance the stability of the material and the solvents in which it can be dispersed/
processed. Again analogies with conventional semiconducting materials can be
12