Perovskite LEDs

 

When consider the LED bulbs, there are three main types. On-chip LED, Remote Phosphor LED, and Real LEDs. In On-chip LEDs, Remote Phosphor LEDs are color down conversion photoluminescence.

The image was taken from www.research.fsu.edu

Blue color LEDs are used as the Backlit in the On-chip LEDs. As we all know Blue (around 450 nm) color has higher energy compared to the other colors (from 500-700 nm).  Then, we are coating the perovskite materials over the top of the On-chip LEDs. In Remote Phosphor LED phosphor coating is applied directly on to blue LEDs to make white light. Electroluminescence is the working principle for real LEDs. Also, real LEDs have glass substrate, hole transport layer, Perovskite material, electron transport layer, & an secondary electrode.

In the process of fabricating perovskite LEDs First, the Indium tin oxide (ITO) coated glass substrate is cleaned via solvent cleaning (soap solution, Acetone, & Alcohol) and oxygen plasma. poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and perfluorinated ionomer (PFI) is then spun-cast. The perovskite layer is spun, then transfer to a thermal evaporator, where about 20 nm 2,2',2''-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) TPBi (hole transport layer), and 60 nm aluminum are then deposited. Then apply a bias to the system and analyze the optoelectronic properties of these devices.

 Link for the original image : https://www.research.fsu.edu/research-offices/oc/technologies/metal-halide-perovskite-phosphors-in-leds-for-full-color-display-and-solid-state-lighting/