  The present work deals with the comparison of sizes, optical and electronic
properties of COOH functionalized CdTe quantum dots (QDs) in freezed solid
polymeric (polyvinyl alcohol (PVA) matrix and in solution phase (water). PVA
has been chosen as host material for guest CdTe QDs because of its unique
properties like hydrophilicity, good thermo stability, and easy process
ability. Experimental absorption, emission, X-Ray diffraction spectra and
electronic band gap have been studied by UV-Vis absorption, luminescence and
X-Ray diffraction spectroscopy. The smaller size of CdTe QDs in solid PVA
polymer matrix (~ 6 nm) and larger band gap of ~9.5 eV validates their quantum
confinement regime in freezed solid phase. The smaller particle size in solid
phase compared to that of the particle size in its solution phase (8 nm)
validates the non existence of agglomeration in solid phase. Appearance of high
intense and wide luminescence emission in solid form proves the strong
candidature of CdTe QDs as promising sensors for today's optoelectronic and
biomedical industry.
