Quasi-two-dimensional perovskites have emerged as a new class of high-performance materials for photoluminescence applications owing to their unique quantum-well structure. Both Dion–Jacobson (DJ) and Ruddlesden–Popper (RP) phase perovskites are attracting considerable attention owing to their obvious improvement in light-emitting diodes, solar cells, and photocatalytic devices. Meanwhile, quasi-two-dimensional perovskites have also shown outstanding performance in laser applications. Because the long-chain organic spacer cations between the lead halide perovskite layers tend to influence the dimensionality, phase distribution, and morphology of quasi-2D perovskite films, it is important to have a comprehensive understanding of the population inversion in quasi-2D perovskites. Herein, we prepared quasi-2D perovskite films with different Dion–Jacobson ratios and compared their morphology, optical characterization, and amplified spontaneous emission (ASE) performance. The results showed that the perovskite films with RP/DJ-mixed quasi-2D materials not only retained the excellent optical properties of the quasi-2D materials but also presented an improved crystallization quality and surface morphology. The ASE threshold of the hybrid perovskite film decreased from 52.2 to 30.1 μJ cm−2, while the gain coefficient was enhanced from 379 to 785 cm−1. Our work demonstrates that RP/DJ quasi-2D perovskite films can be a kind of promising waveguide material for ASE. Normally, DJ perovskite materials show good carrier transport, which is beneficial to the realization of electric pumping lasers based on perovskite materials.
