Bright and Color-Tunable Single Layer Perovskite Host-Ionic Guest Light Emitting Electrochemical Cells

TL;DR

This paper demonstrates a simple, efficient single-layer perovskite light-emitting electrochemical cell using a CsPbBr3 host and a novel ionic iridium guest, achieving high luminance, color tunability, and stable operation.

Contribution

It introduces a new ionic guest and optimized blend for perovskite PeLECs, enabling high performance, color reconfigurability, and stability in a single-layer device.

Findings

Achieved 10600 cd/m2 luminance at 11.6 cd/A

Voltage-dependent color tuning from orange-red to green

Stable operation for over 40 hours under constant current

Abstract

Perovskite light emitting devices have drawn considerable attention for their favorable optoelectronic properties. High carrier mobilities make perovskites excellent candidates as host materials in electroluminescent devices. To achieve high performance in a simple single layer device, we employed a CsPbBr3 perovskite host and a novel ionic iridium complex guest along with a polyelectrolyte to demonstrate efficient light emitting electrochemical cells (PeLECs). For an optimal guest/host blend, 10600 cd/m2 luminance at 11.6 cd/A and 9.04 Lm/W are achieved at 4.1 V. These devices showed voltage-dependent electroluminescence color proceeding from orange-red to green, facilitated by the reconfigurable ionic materials blend. Optimized devices exhibited stable operation under constant current driving, maintaining >630 cd/m2 emission for 40 h. Our rationally-designed ionic guest at an optimal concentration of the host produced efficient (>90%) Forster energy transfer and improved thin film morphological for high performance PeLEC operation enabled by ionic migration to interfaces