论文标题
无铅二维碘化物钙钛矿中的结构重建导致高量子产量发射
Structural Reconstruction in Lead-free Two-dimensional Tin Iodide Perovskites Leading to High Quantum Yield Emission
论文作者
论文摘要
我们报告了通过热注射方法合成的胶体二维碘化物纳米片的结构重建诱导的高光致发光量子产率为25％。室温下，在洗涤或暴露于光线时，室温下的辛吉利铵锡钙晶的红色红色纳米片转换为白色六角形纳米片。这种结构变化将带隙从2.0 eV增加到3.0 eV，从而引起了较大的stokes偏移和宽带发射。此外，测量了纳米片的长光致发光寿命约为1微秒。如此长的宽阔和强烈的光致发光，预计具有较大的Stokes Shift将起源于结构重建过程中形成的锡碘化物簇。立体活性5S2单对锡（II）离子散布着白色六边形纳米片的激发状态几何形状，并促进了自被捕的激子的形成。这种宽带和强烈发射的金属卤化物纳米片对于发射白光二极管有望。
We report a structural reconstruction-induced high photoluminescence quantum yield of 25% in colloidal two-dimensional tin iodide nanosheets that are synthesized by a hot-injection method. The as-synthesized red-colored nanosheets of octylammonium tin iodide perovskites at room temperature transform to white hexagonal nanosheets upon washing or exposure to light. This structural change increases the bandgap from 2.0 eV to 3.0 eV, inducing a large Stokes shift and a broadband emission. Further, a long photoluminescence lifetime of about 1 microsecond is measured for the nanosheets. Such long-lived broad and intense photoluminescence with large Stokes shift is anticipated to originate from tin iodide clusters that are formed during the structural reconstruction. Stereoactive 5s2 lone pair of tin (II) ions perturbs the excited state geometry of the white hexagonal nanosheets and facilitates the formation of self-trapped excitons. Such broadband and intensely emitting metal halide nanosheets are promising for white light-emitting diodes.
