For highly efficient perovskite light-emitting diode (PeLED), fine control of perovskite grain size and effective energy band alignment is essential. Herein, we demonstrate a uniform ChhNhhPbBn (MAPbBn<) perovskite thin film as an emitting layer by using nano grain engineering with non-solvent treatment. Furthermore, the effects of solution-processed electron transport materials, including BCP, TPBi and PCBM, on device performance are investigated. As a results, high efficiency PeLEDs are successfully demonstrated with BCP due to superior electron transport and hole blocking property.