Effect of Bathocuproine Organic Additive on Optoelectronic Properties of Highly Efficient Methylammonium Lead Bromide Perovskite Light-Emitting Diodes

Recent studies have shown that introductions of some organic additives are beneficial for optimizing organic–inorganic hybrid perovskite (OIHP) optoelectronic properties to promote their industrial realizations. In this work, a typical organic molecule bathocuproine (BCP) has been utilized during the preparation of a methylammonium lead tribromide (CH3NH3PbBr3) precursor, and a perovskite-based light-emitting diode (PeLED) consisting of ITO(glass)/PEDOT:PSS/CH3NH3PbBr3:BCP/Bphen/Ag was fabricated. Because of the participation of BCP, PeLED exhibits excellent light-emissive properties without any crystalline distortions of CH3NH3PbBr3, such as low turn-on voltage Vturn-on = 2.5 V, high luminescent intensity L = 1.4 × 104 cd/m2, and high efficiency η = 3.2 cd/A. On the basis of electronic transport and optically spectroscopic characterizations, it has been verified that such remarkable and desirable enhancements are attributed to three contributions: (i) a decrease of CH3NH3PbBr3 crystalline grain size, (ii) a reduction of trap density (nt), and (iii) an improvement of electronic charge mobility (μe). We thus believe that not only may this work pave the way for the present fast development of PeLEDs, but it also provides some insightful physics studies for device physicists.