2021/09/21 by Santanu Pradhan, Pradhan, Santanu, Mariona Dalmases +5
Engineering · Materials Science · Physics and Astronomy · #Applied Physics (physics.app-ph) #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Nanocluster Synthesis and Applications #Optics (physics.optics) #Quantum Dots Synthesis And Properties #Semiconductor materials and interfaces
paper · pdf · doi:10.48550/arxiv.2109.10146
openalex publication_date 2021/09/21 · openalex created_date 2022/07/25 · openalex updated_date 2026/08/01
Unbalanced charge injection is deleterious for the performance of colloidal\nquantum dot (CQD) light emitting diodes (LEDs) as it deteriorates the quantum\nefficiency (QE), brightness and operational lifetime. CQD LEDs emitting in the\ninfrared have previously achieved high quantum efficiencies but only when\ndriven to emit in the low radiance regime. At higher radiance levels, required\nfor practical applications, the efficiency decreased dramatically in view of\nthe notorious efficiency droop. Here we report a novel methodology to regulate\ncharge supply in multinary bandgap CQD composites that facilitates improved\ncharge balance. Our approach is based on engineering the energetic potential\nlandscape at the supra-nanocrystalline level that has allowed us to report\nshort-wave infrared (SWIR) PbS CQD LEDs with record-high external QE in excess\nof 8%, most importantly, at a radiance level of ~ 5 WSr-1m2, an order of\nmagnitude higher than prior reports. Furthermore, the balanced charge injection\nand Auger recombination reduction has led to unprecedentedly high operational\nstability with radiance half-life of 26068 hours at a radiance of 1Wsr-1m-2.\n