High‐Efficiency, Solution‐Processed White Quantum Dot Light‐Emitting Diodes with Serially Stacked Red/Green/Blue Units

Abstract

Despite the fast advances in monochrome quantum dots (QDs) based light‐emitting diodes (QLEDs), the performance for white QLEDs (WQLEDs) with great potential for illumination and backlight applications to date has fallen short of that of state‐of‐the‐art white organic LEDs. Here, a highly efficient all‐solution‐processed WQLED with a serially stacked red/green/blue tandem structure, which displays an almost perfect white emission with the Commission Internationale de l'Enclairage coordinates of (0.34, 0.33) is reported. The white device exhibits peak current efficiency of 79.9 cd A−1 and external quantum efficiency of 28.0%, which are the highest efficiency values ever reported in WQLEDs. The record performance for the WQLEDs is achieved by the effective interconnecting layer with excellent charge generation and the insertion of a polyethylenimine ethoxylated interlayer between the ZnO electron transport layer and QDs emissive layer in each unit for better balancing charge injection and suppressing the quenching of QDs emission due to the contact with ZnO.

Improvement in hole transporting ability and device performance of quantum dot light emitting diodes

“…The comparison of the device performance of green QLEDs from the previous literature studies and our study is listed in Table 2. [4][5][6]10,20,24,25,27,29,30 It is seen that our optimized device IV comprising PEDOT:PSS + BYK-P105 as the HTL and PEIE-modied ZnO as the ETL showed a very high brightness and comparable current efficiency compared with other studies. Therefore, blending BYK-P105 with PEDOT:PSS provides a successful approach to improve the performance of QLEDs.…”

Ultrahighly Efficient White Quantum Dot Light‐Emitting Diodes Operating at Low Voltage

“…[1,[10][11][12][13][14] However, when the practical applications of QLEDs in general illumination and backlighting are considered, achieving efficient white emission devices, i.e., devices in which red, green, and blue colors are simultaneously stimulated, is highly desired. [15][16][17][18][19][20] These results validate our approach as a promising way for achieving high-performance white QLEDs with low power consumption that hold promise for applications in next-generation lighting and display systems.…”

Promoted Hole Transport Capability by Improving Lateral Current Spreading for High‐Efficiency Quantum Dot Light‐Emitting Diodes

“…[45,46] Moreover, the energy band gap and electron affinity for ZnO, CdSe/ZnS, CBP, MoO 3 , and HAT-CN were also important parameters for the simulation. [47,48]…”