Hybrid light emitting diodes and photodetectors using polymers and perovskites via electrospraying and ink-jet printing

Abstract

This dissertation focuses on the opto-electronic devices fabrication, including LEDs and PDs using organic/inorganic hybrid materials including triple-cation perovskite, conjugated polymers, and n-type Si via spin-coating, electrospraying and ink-jet printing fabrication techniques. Followed by an extensive literature review about the primary materials (perovskite, polymers), devices (LED, photodetectors), and fabrication techniques (electrospraying, inkjet printing), experimental and characterization methods are explained. For device fabrication, firstly, we investigate the performances of the LEDs fabricated with triple-cation perovskite by spin-coating. During the fabrication, crystallinity modification techniques are used to improve the device performances. However, the emission wavelength is fixed for this kind of devices unless the perovskite cooking recipe is modified. Secondly, conductive and fluorescent conjugated polymers are introduced to alter the emission wavelength of the LEDs by controlling their ratio of mixture. Because of the limitations of the spincoating technique in forming multi-layered architecture, we have implemented electrospraying to overcome such difficulties. Using electrospraying as the new fabrication technique, color-tunable LEDs are fabricated and characterized. Even though, electrospraying has many advantages compared to spin-coating, the stability of the electrospraying process and its precise control are still hard to achieve. Ink-jet printing could be a method to improve the fabrication technique with the advantages of material efficient, stable and precise control. In the end, silicon-based photodetectors fabricated by ink-jet printing are demonstrated. Overall, this thesis represents a favorable route towards efficient and cost-effective opto-electronic device fabrication.

Date	14 Aug 2023
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Sylvain G. Cloutier (Supervisor)