Highly Efficient Hybrid Perovskite/Organic Tandem White Light Emitting‐Diodes with External Quantum Efficiency Exceeding 20%

Abstract

Perovskite light‐emitting diodes (PeLEDs) have shown great potential for low‐cost display and lighting technologies, and all‐inorganic blue PeLEDs are recognized as a promising substitute for blue fluorescent/phosphorescent organic light‐emitting diodes (OLEDs) owing to their superior color purity and great stability potential. However, confined by the solution fabrication process, depositing multi‐layered white PeLEDs remains a challenge. Here, a newly designed hybrid perovskite/organic tandem white LED (POTWLED), integrated with a bottom blue PeLED unit and a top orange/(orange + red) OLED unit, to prevent damage to the underlying perovskite layer caused by the deposition of the top emitting layers, is reported. To optimize the performance of POTWLEDs, a conductive passivator of 2,8‐bis(diphenylphosphoryl)dibenzo[b,d] thiophene, with a strong surface binding group of P═O, is introduced to passivate perovskite defects, which promotes a maximum external quantum efficiency (EQE) of 17.3% for blue PeLEDs with an emission peak at 488 nm. As a result, based on the optimized blue PeLED units, a maximum EQE of 23.9% with a low color temperature of 2522 K is obtained for POTWLEDs, which is the highest efficiency for perovskite‐based WLEDs, illustrating the great potential of the hybrid tandem device in fabricating high‐performance perovskite‐based WLEDs.

Efficient and stable hybrid perovskite-organic light-emitting diodes with external quantum efficiency exceeding 40 per cent

“…For example, a quantum dot liquid crystal TV is fabricated by applying quantum dot patterned color filters and liquid crystal display 28 , 29 , and a white light LED is prepared by combining QLEDs with OLEDs 30 . Tandem LEDs that connect two or more electroluminescence (EL) units of LEDs through a unique interconnecting layer (ICL) can offer an effective way to integrate the different technologies for better display applications 31 – 34 . Another important advantage of tandem devices is that the operational lifetime can be dramatically improved due to the reduced current under the same luminance, which is especially beneficial for the PeLEDs.…”

Roadmap on perovskite light-emitting diodes

“…The inset indicates the precursor material cost of representative emitters in each field [12]. [1,10,11,20,31,32,34,36,[38][39][40][41][42][43][44][45][46][47][48][49][50][51][52]. (c) Evaluation of perovskite lighting from emitters to devices to applications.…”

“…Efficiency chart of PeLEDs with (a) various colors and (b) various perovskite forms. Data was collected from[1,10,11,20,31,32,34,36,[38][39][40][41][42][43][44][45][46][47][48][49][50][51][52]. (c) Evaluation of perovskite lighting from emitters to devices to applications.…”

In-Situ Probing the Degradation Behavior of the Organic–Inorganic Hybrid Perovskite Film by Scanning Tunneling Microscopy

“…Solution-processed organic–inorganic hybrid perovskite (OIHP) films are promising materials for use in future photovoltaic devices. − The stability of OIHP films is one of the key issues to overcome compared with other competing commercial products. It has been observed that OIHP films are very sensitive to the environment conditions and can degrade quickly in the external environment such as light, temperature, etc., , decomposing into metal halides and gases .…”