Electronic transport of n-type CdSe quantum dot films: Effect of film treatment

Abstract

Solid films of CdSe colloidal quantum dots are conductive when reduced by electrochemistry. The dark conductivity and the photoconductivity of these n-type CdSe nanocrystalline solids have been investigated as a function of film treatment. When the films are treated with NaOH, a carrier mobility of ∼10−2cm2∕Vs and a charging/discharging time of ∼10ms are obtained. Under an excitation intensity of ∼0.75mW∕cm2, a significant photoconductivity of ∼10−3Scm−1 has been observed. The high mobility allowed demonstrating the operation of a field effect transistor.