Yellow Light Energy Transfer Emitting Diodes Based on mixed Quasi-2D   Perovskites
  The new class of hybrid organic-inorganic semiconductor (HOIS) materials, based on halide perovskites, is constantly being pursued for applications such as Light Emitting Diodes (LEDs) and solar cells, due to their momentous optoelectronic properties. In this work, we present a single layer LED that operates due to energy transfer effects as well as a simple, instant and low cost method for its fabrication. A LED device based on a mixture of zero dimensional (OD) (CH 3 NH 3 ) 4 PbI 6, two dimensional (2D) (F- C 6 H 4 CH 2 CH 2 NH 2 ) 2 PbI 4 and three dimensional (3D) (CH 3 NH 3 )PbI 3 HOIS, is presented for the first time. The final composite material manifests simple, yet unique energy transfer optical effects, while its electroluminescence exhibits excitonic recombination bright yellow light, peaked at 592 nm. LED device fabricated under ambient air, readily functions at room temperature and low voltages. As for the active layer, it exhibited substantial film continuity in any form of deposition. Finally, with appropriate mixtures, it is possible to create films containing phase changes that exhibit dual color emission, here presented as yellow-green. 
Dionysios Papadatos, Anastasia Vassilakopoulou and Ioannis Koutselas
physics.optics cond-mat.mes-hall cond-mat.mtrl-sci physics.chem-ph