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 (CH 3 NH 3 PbBr 3 ) precursor, and a perovskite-based light-emitting diode (PeLED) consisting of ITO(glass)/PEDOT:PSS/CH 3 NH 3 PbBr 3:BCP/Bphen/Ag was fabricated. Because of the participation of BCP, PeLED exhibits excellent light-emissive properties without any crystalline distortions of CH 3 NH 3 PbBr 3, such as low turn-on voltage V turn-on = 2.5 V, high luminescent intensity L = 1.4 × 10 4 cd/m 2, 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 CH 3 NH 3 PbBr 3 crystalline grain size, (ii) a reduction of trap density ( n t ), and (iii) an improvement of electronic charge mobility ( μ e ). 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.