Chemical Sensitivity of Luminescent Epitaxial Surface InP Quantum Dots

Abstract

Surface InP quantum dots grown by gas source molecular beam epitaxy on In 0.48 Ga 0.52 P buffer layer lattice matched to GaAs substrate shows a broad-band near-infrared photoluminescence ranging from 750 to 865 nm dependent on their dimensions. A reversible luminescence intensity enhancement has been observed when the quantum dots were exposed to vapours of different chemical solvents with the highest sensitivity for alcohol (methanol and ethanol) vapours. The luminescent behaviour is dependent on the solvent type and concentration. The peak energy and band shape of the luminescence are not affected by the solvent vapour.

Chemical sensitivity of InP/In0.48Ga0.52P surface quantum dots studied by time-resolved photoluminescence spectroscopy

“…Such an effect is particularly evident for methanol where a 15% enhancement of the fast decay time has been measured. The results are fully compatible with a model we recently suggested [8,16,18] based on the saturation effect of the QD non-radiative surface states by the vapour organic molecules. The model suggested is here experimentally confirmed for the first time while the alternative explanation of an off-set of the air potential barrier due to the adsorption of chemicals is ruled out.…”

“…In previous studies [8,[15][16][17][18] we investigated the chemical sensitivity of InP/InGaP SQDs. We found that the composition of the surrounding gaseous environment strongly affects their PL intensity.…”

“…In our previous works, we characterized the methanol sensitivity of InP/InGaP SQDs by continuous wave photoluminescence (CW-PL) spectroscopy [8,[15][16][17][18]. We observed a rapid and reversible increase in the PL intensity, proportional to the methanol concentration.…”

External Parameters Affecting on the Photoluminescence of InAs Spherical Layer Quantum Dot

“…The CQDs showed UV absorption at about 346 nm and a broad spectrum of photoluminescence with quantum yield of 49.9%. Roberta De Angelis et al [9] investigated the Chemical Sensitivity of Luminescent Epitaxial Surface InP Quantum Dots, where a broad-band near-infrared photoluminescence ranging from 750 to 865 nm was reported from the surface InP quantum dots grown by gas source molecular beam epitaxy on In 0.48 Ga 0.52 P buffer layer lattice matched to GaAs substrate. When the quantum dots exposed to vapors of different chemical solvents with the highest sensitivity for alcohol (methanol and ethanol) vapours a reversible luminescence intensity enhancement has been observed.…”

Colloidal InSe nanostructures: Effect of morphology on their chemical sensitivity to methanol and formaldehyde fumes

“…This happens as a consequence of the change in the density of states as a result of spatial confinement [2]. In addition, the nano-size provides the semiconductor nanocrystals with a high surface area which is a relevant condition for adsorption of the analyte vapour [3][4][5][6]. The process of the analyte detection on the semiconductor surface is usually due to the changes in the band bending or surface recombination velocity caused by the bound species from the analytesubstrate surface states interactions.…”