Nonionic surfactant assisted in-situ growth of all-inorganic perovskite film for bright pure red light-emitting devices

Smooth and uniform morphology with low trap defects is important for the development of efficient perovskite light-emitting devices (PeLEDs). Pure red PeLEDs based on a facile one-step solution method still suffer moderate electroluminescent performance due to poor controllability for film growth. Here, we take advantage of coor-dination effects from surfactant additives to control the perovskite crystallization and suppress the nonradiative recombination. It is found that the introduction of Tween-80 (T80) in the precursor could not only improve the surface morphology with decreased roughness (RMS of 1.43 nm) but also enhance the radiative efficiency. As a result, efficient pure-red perovskite light-emitting devices were obtained with a brightness of 891 cd/m2, a current efficiency of 2.42 cd/A, and an EQE of 4.17 %. Our results would shed light on the film morphology control through additive engineering towards high-performance PeLEDs.