Metal halide perovskite nanocrystals have demonstrated their potential as light sources when forming part of efficient light emitting diodes (LEDs). However, operational stability and efficiency are compromised primarily because of unstable hole transport layers. In this work, we report the application of two carbazole-based self-assembled molecules (SAMs) as hole injecting materials in perovskite-based LEDs. Their structures differ in one phenyl ring in the bridge; however, the extra ring provides more stability to the devices, even surpassing the one obtained with the widely used polymer PTAA. In addition, due to the structural and electronic characteristics of the SAMs, the efficiency of the devices is also increased.