Low Power Consumption Red Light-Emitting Diodes Based on Inorganic Perovskite Quantum Dots under an Alternating Current Driving Mode

Abstract

Inorganic perovskites have emerged as a promising candidate for light-emitting devices due to their high stability and tunable band gap. However, the power consumption and brightness have always been an issue for perovskite light-emitting diodes (PeLEDs). Here, we improved the luminescence intensity and decreased the current density of the PeLEDs based on CsPbI3 quantum dots (QDs) and p-type Si substrate through an alternating current (AC) driving mode. For the different driving voltage modes (under a sine pulsed bias or square pulsed bias), a frequency-dependent electroluminescent (EL) behavior was observed. The devices under a square pulsed bias present a stronger EL intensity under the same voltage due to less thermal degradation at the interface. The red PeLEDs under a square pulsed bias driving demonstrate that the EL intensity drop-off phenomenon was further improved, and the integrated EL intensity shows the almost linear increase with the increasing driving voltage above 8.5 V. Additionally, compared to the direct current (DC) driving mode, the red PeLEDs under the AC condition exhibit higher operating stability, which is mainly due to the reducing accumulated charges in the devices. Our work provides an effective approach for obtaining strong brightness, low power consumption, and high stability light-emitting devices, which will exert a profound influence on coupling LEDs with household power supplies directly.

Facile Synthesis and Optical Properties of CsPbX3/ZIF-8 Composites for Wide-Color-Gamut Display

“…All-inorganic CsPbX 3 (X = Cl, Br, and I) perovskite quantum dots (QDs) have drawn extensive attention over the past years due to high-fluorescence quantum efficiency, narrow-tunable emission, easy solution-based preparation, and short-carrier lifetime, which endows them with great prospect in light-emitting devices (LEDs), solar cells, low-threshold lasers, photoelectric detectors, and visible-light communication applications [1,2,3,4,5]. However, since the perovskite QDs are ionic crystals and their formation energy is low, their crystal structures are easily damaged under different exposures such as light, heat, moisture, oxygen, etc., which could result in the degradation of photoelectric properties [6].…”

Enhanced Near‐Infrared Perovskite Light‐Emitting Devices by Introducing Choline Chloride Layer

“…The EL intensity of the AC‐driven device decreases more slowly and reaches a T 50 of more than 170 min under the high current density of 300 mA cm −2 , four times that under DC mode. As discussed in previous work, [ 16,17 ] the improvement of EL intensity and stability in AC driving mode can be attributed to the frequent reversals of the applied bias, which could suppress heating in continuous operation and decrease charge accumulation.…”

“…From the viewpoint of device applications, it is also an interesting topic to fabricate NIR PeLEDs based on the Si platform to develop multifunctional chips. [13][14][15][16][17][18] However, the efficiency and stability of NIR PeLEDs on Si is still unsatisfactory, which is a challenge nowadays. the cross-section scanning electron microscope (SEM) image of the PeLED is shown in Figure 1a.…”

Stability of electroluminescent perovskite quantum dots light‐emitting diode

“…Reproduced with permission. [123] Copyright 2018, MDPI surface ligands such as quaternary ammonium salts, phosphonic acids, and amphoteric molecules with appropriate chain length will not only show the stronger adhesion to the surface of nanocrystals, protecting QDs from being destroyed during purification and film formation, but also adjust proper carrier injection capability for the balanced charge-carrier transport. (ii) Robust constituent layers with efficient and balanced carrier transport capacity.…”

“…[191,192] The performance drops off dramatically at high driving voltage due to Joule heat and charge accumulation. The alternating current (AC) condition with the reversal voltage and a short operating time can solve the problems mentioned above [122,123] (Figure 11B-F). Two factors can be used to explain the improvement of device performance under AC driving mode.…”