Transparent quantum dot light-emitting diodes with a current focusing structure

We report transparent quantum dot light-emitting diodes with a current focusing structure. By depositing a SiO2 thin film to form the current focusing structure, the DC density and luminance significantly increased to over 8700 mA/cm2 and 360 000 cd/m2, respectively. The emission spectra and current densities as functions of SiO2 thickness and aperture width have been investigated and discussed. This current focusing design is proved effective and can be further applied to other planar light-emitting diode devices.