Effect of cadmium-selenide quantum dots on the conductivity and photoconductivity of nanocrystalline indium oxide

Abstract

The effect of cadmium-selenide quantum dots addition on the electrical and photoelectric properties of nanocrystalline indium oxide with nanocrystal dimensions in the range from 7 to 40 nm is studied. By impedance spectroscopy, it is shown that the addition of quantum dots substantially influences the resistance of interfaces between In 2 O 3 crystals. A change in the character of the photoconductivity spectrum of In 2 O 3 upon the addition of CdSe quantum dots is detected, and it is established that this change depends on the In 2 O 3 -nanocrystal dimensions. An energy band diagram is proposed to explain the observed change in the photoconductivity spectrum of In 2 O 3 upon the addition of CdSe quantum dots.

Visible light activation of room temperature NO 2 gas sensors based on ZnO, SnO 2 and In 2 O 3 sensitized with CdSe quantum dots

“…Our recent investigations [35] of the effect of CdSe QDs on the electrical properties of nanocrystalline In 2 O 3 by impedance spectroscopy demonstrated that the addition of QDs substantially influences the resistance of interfaces between In 2 O 3 crystals. However, the behavior of the frequency dependence of the samples conductivity is defined only by the nanocrystalline structure of semiconductor matrix.…”

Light Activation of Nanocrystalline Metal Oxides for Gas Sensing: Principles, Achievements, Challenges

“…The use of CdSe [ 160 , 161 , 162 , 163 , 164 , 165 ] and PbS [ 166 ] quantum dots for the creation of photo- and gas sensitive nanocomposites is described in the literature. The sensor and photoelectric properties of nanocomposites based on semiconductor metal oxides ZnO, SnO 2 , In 2 O 3 , and CdSe colloidal QDswere studied in [ 161 , 162 , 163 , 164 ]. For sensitization, spherical CdSe quantum dots with an average diameter of 2.7 nm, stabilized with oleic acid, were used.…”