High efficiency Quasi-2D Organic/Inorganic Hybrid Perovskite Light Emitting Diodes using phenylethylene ammonium lead bromide

Abstract

Recently organic ammonium lead halide perovskite materials become promising materials for optoelectronic devices. Because it has high exciton diffusion length and high absorption coefficient perovskite material become one of the most promising materials for solar cells. However because of its unique structure, perovskite materials can work as light-emitting diodes (LEDs) also. This perovskite LEDs can be fabricated by solution process and it has very narrow full width at half maximum (FWHM). However its device properties are very low compared to other light emitting devices. Many research group has been used methyl ammonium lead bromide to make perovskite LEDs. However, we add new perovskite material, phenylethylene ammonium lead bromide to methyl ammonium lead bromide. This mixture makes different perovskite structure which is called quasi-2D perovskite structure. We fabricate perovskite light-emitting diodes using quasi-2D perovskite materials with different ratio of contents. We use Buf-HIL and 1,3,5-tris(N-phenylbenzimiazole-2-yl)benzene (TPBi) as a hole injection layer and electron transfer layer respectively. We made quasi-2D perovskite film by spin coating the mixed two precursor solution. With this method quasi-2D perovskite film is composed with different quasi-2D crystals which has different bandgaps. However only one crystal which has similar bandgap with methyl ammonium lead bromide can luminance both photoluminance (PL) and electroluminance(EL). These quasi-2D perovskite LEDs shows higher device performance than perovskite LEDs using methyl ammonium lead bromide or phenylethylene ammonium lead bromide, and MPEA16 had current efficiency 4.90 cd/A, and maximum luminance 2934.6 cd/m2.