Prominent Heat Dissipation in Perovskite Light-Emitting Diodes with Reduced Efficiency Droop for Silicon-Based Display

Abstract

Solution-processed perovskite light-emitting diodes (LEDs) possess outstanding optoelectronic properties for potential solid-state display applications. However, poor device stability results in significant efficiency droop partly being ascribed to Joule heating when LEDs are operated at high current densities. Herein, we used monocrystal silicon (c-Si) as the substrate and a charge injection layer to alleviate the thermal affection in perovskite LED (PeLED). By incorporating silicon oxide (SiO x ) and poly­[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(4,4′-(N-(4-butylphenyl) (TFB) layers to tune the charge injection balance in a c-Si-based device, a PeLED achieves an external quantum efficiency of 2.12% with a current efficiency of 6.06 cd A–1. Benefiting from excellent heat dissipation of c-Si, the PeLEDs display reduced efficiency droop and extended operational lifetime. Furthermore, both electroluminescent (EL) dynamic information and static pattern displays of a c-Si-based PeLED have been successfully demonstrated. These results reveal the feasibility of potential practical c-Si-based PeLEDs with reduced efficiency droop for EL display applications.

Reality or fantasy—Perovskite semiconductor laser diodes

“…This is equivalent to replace the materials of the laser diodes with a higher value of k T but without changing the corresponding electrical and optical properties. Previous investigation has verified that the use of monocrystal Si as the substrate and as a charge injection layer instead of using ITO/glass substrate in perovskite LEDs can alleviate the influence of thermal effects 94 . This is because κ T (~150 W·m −1 ·K −1 ) of monocrystal Si is much higher than that of glass (~1 W·m −1 ·K −1 ) at room temperature 96 .…”

“…This is because the portion of electrical power not contributed to light generation will lead to “heating,” and the temperature will increase with the increase of injection current. From the previous study on the heat generation in LEDs under CW operation, the increase in temperature can be as much as ~20°C per 100 mA/cm 2 94 . Therefore, heating is the main problem for using the available LED architectures as an excitation source.…”

Recent Progress on Patterning Strategies for Perovskite Light‐Emitting Diodes toward a Full‐Color Display Prototype

“…Therefore, patterning all the functional layers or introducing an insulating interfacial layer between the charge transporting layers and perovskite emitters may partially help to overcome the aforementioned problems. In spite of the low efficiencies of PeLEDs based on perovskite patterns, the feasibility of potential applications of a dynamic digit 7‐segment display and a static EL image with 200 dpi was successfully demonstrated, [ 91 ] as shown in Figure 11b.…”

“…Reproduced with permission. [ 91 ] Copyright 2020, American Chemical Society. c) A green flexible PeLED fabricated by the vacuum thermal evaporation method before and after stretch.…”

Advances in Perovskite Light-Emitting Diodes Possessing Improved Lifetime

“…For example, the stability of PeLEDs will be improved if defects in perovskite emitting materials are passivated (e.g., the use of 5-aminovaleric acid to passivate defects) [32][33][34]. The device stability will be also enhanced if good charge balance is accomplished (e.g., the improvement of electron injection to balance the hole injection) [35][36][37]. On the other hand, despite optical effects (e.g., light outcoupling) and advanced encapsulations have been scarcely investigated to improve the lifetime of PeLEDs, these two factors are believed to be significant to decide the stability according to the evolution of OLEDs and Cd-based QD-LEDs [38][39][40][41][42][43].…”