ABSTRACT
This chapter presents experimental demonstrations of the Multiple-Quantum Dots (MQDs) construction. Control of dimensionality is an important issue to improve various kinds of optical and electronic properties of materials. Dimensionality control between zero and one, that is, the sizes of quantum dots, can be achieved by inserting molecular units that disconnect the spread of π-electrons in conjugated polymer wires. The monomolecular-step polymer wire growth process can be achieved by molecular layer deposition (MLD). MLD operation can be obtained by sequentially switching the three valves for molecular gas injection. Carrier gas of nitrogen is employed to introduce molecular gases of terephthalaldehyde, p-phenylenediamine, and oxalic dihydrazide in temperature-controlled molecular cells onto a glass substrate surface. In terephthalaldehyde, p-phenylenediamine, and diaminodiphenyl ether, the absorption band exhibits further higher-energy shift, indicating strong electron confinement in the short quantum dots. Poly-AM, OTPTPT, OTPT, and OT were experimentally fabricated by three-molecule MLD.
