Bare quantum dots superlattice photonic devices

Abstract

Manipulation of the passivation ligands of colloidal quantum dots and use in QD electronics. A multi-step electrostatic process is described which creates bare QDs, followed by the formation of QD superlattice via electric and thermal stimulus. Colloidal QDs with original long ligands (i.e. oleic acid) are atomized, and loaded into a special designed tank to be washed, followed by another atomization step before entering the doping station. The final step is the deposition of bare QDs onto substrate and growth of QD superlattice. The method permits the formation of various photonic devices, such as single junction and tandem solar cells based on bare QD superlattice, photodetectors, and LEDs. The devices include a piezoelectric substrate with an electrode, and at least one layer of bare quantum dots comprising group IV-VI elements on the electrode, where the bare quantum dots have been stripped of outer-layer ligands.