## 1 Introduction  
In recent years, organic inorganic hybrid perovskites have received wide attention and investigation as the most competitive candidates in photovoltaic field development. Organic inorganic hybrid perovskites are a new subclass of material self-assembled at the molecular scale from organic and inorganic components [1; 2; 3]. The crystal structure of a perovskite can be described with the chemical formula ABX\({}_{3}\), in which A-sites are the organic ammonium cations, B-sites are the inorganic metal cations, and X-sites are the halide anions. The B-site cation is six-coordinated by the X-site anion to form [BX\({}_{6}\)] octahedrons, which are corner-sharing to constitute three-dimensional frameworks [4; 5]. These compounds have multiple quantum well structures with alternating organic and inorganic layers [6]. In these compounds, the excitons possess larger binding energy due to quantum confinement effects, which displays excellent optical properties such as second harmonic generation, exciton absorption and emission [7; 8; 9; 10; 11]. These properties make organic inorganic hybrid perovskites great candidates for applications in solar cells [12], electroluminescent devices [13; 14; 15] and radiation detection [16]. The perovskite solar cells with all solid state structure can prevent the problems from the liquid electrolyte and exhibit high power conversion efficiency (PCE), displaying great potential in photovoltaic devices. In 2009, [PERSON] et al. [17] firstly studied the solar cells with the perovskite CH\({}_{3}\)NH\({}_{3}\)PbI\({}_{3}\), yielding a PCE of 3.8% due to the lower open voltage. In 2011, [PERSON] et al. [18] synthesized a series of the perovskites (C\({}_{6}\)H\({}_{13}\)NH\({}_{3}\))\({}_{2}\)(CH\({}_{3}\)NH\({}_{3}\))\({}_{n-1}\)Pb\({}_{n}\)I\({}_{3n+1}\), and investigated the effects of the inorganic-sheet number on the crystal structure, bandgap energy, exciton binding energy and photoluminescence emission. In 2013, [PERSON] et al. [19] synthesized several perovskites CH\({}_{3}\)NH\({}_{3}\)SnI\({}_{3}\), HC(NH\({}_{2}\))\({}_{2}\)SnI\({}_{3}\), CH\({}_{3}\)NH\({}_{3}\)PbI\({}_{3}\), HC(NH\({}_{2}\))\({}_{2}\)PbI\({}_{3}\) and CH\({}_{3}\)NH\({}_{3}\)SnI\({}_{1-x}\)PbxI\({}_{3}\), and studied the structure, morphology, phase transition and photoluminescence. In 2014, [PERSON] et al. [6] prepared three perovskitesites (C\({}_{4}\)H\({}_{9}\)NH\({}_{3}\))\({}_{2}\)PbBr\({}_{4}\), (C\({}_{6}\)H\({}_{5}\)CH\({}_{2}\)NH\({}_{3}\))\({}_{2}\)PbBr\({}_{4}\) and (C\({}_{6}\)H\({}_{5}\)C\({}_{2}\)H\({}_{4}\)NH\({}_{3}\))\({}_{2}\)PbBr\({}_{4}\), investigating the effects of organic moieties on luminescence properties of perovskite compounds. In 2015, [PERSON] et al. [13] studied the performance of light-emitting diodes based on perovskite CH\({}_{3}\)NH\({}_{3}\)PbBr\({}_{3}\), and a high luminance up to 1500 cd/m\({}^{2}\) was achieved. In 2018, [PERSON] et al. [20] studied solar cells with the inverted planar heterojunction perovskite, yielding a PCE of 21% due to the elimination of nonradiative charge-carrier recombination. [PERSON] et al. [21] studied the photoluminescence of the perovskite CH\({}_{3}\)NH\({}_{3}\)PbBr\({}_{3}\), discovering the photoluminescence quantum yield (PLQY) increased with decreasing crystal size and explained the phenomenon. Organic inorganic hybrid perovskites combine distinct properties of organic and inorganic components within a single molecular composite. The inorganic component forms the octahedral framework by ionic bonds, to provide good conductivity and carrier mobility. The organic component facilitates the self-assembly, enabling the materials to be deposited using a simple way. These properties can be easily controlled by changing the organic ammonium, inorganic metal or halide [22]. Research on perovskites is now focusing on solar cells and light-emitting diodes, however reports on the photoluminescence properties of the perovskites with the two-photon excitation are rarely seen.