Zhai Wenhao, Ge Chaoyang, Fang Xin, Zhang Kun, Tian Cheng, Yuan Kai, Sun Shuren, Li Yanping, Chen Weixi, Ran Guangzhao
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University Beijing 100871 China
RSC Adv. 2018 Apr 18;8(26):14527-14531. doi: 10.1039/c8ra00583d. eCollection 2018 Apr 17.
We adopt an acetone vapour-assisted method to grow high quality single-crystalline microplates of two-dimensional (2D) perovskite, 2-phenylethylammonium lead bromide [(CHCHNH)PbBr]. The microplates, converted from the spin-coated films, are well-defined rectangles. Temperature dependent photoluminescence (PL) spectroscopy shows that the band gap PL is enhanced markedly with increasing temperature up to 218 K, accompanied by the quenching of the PL related to the trap states, which perhaps results from the exciton-phonon couplings. The optical phonon energy around 50 meV and the exciton binding energy around 120 meV are derived by fitting the band gap PL linewidths and intensities at different temperatures, respectively.
我们采用丙酮蒸汽辅助法生长高质量的二维（2D）钙钛矿单晶微板，即2-苯乙铵溴化铅[(CHCHNH)PbBr]。由旋涂薄膜转化而来的微板为轮廓清晰的矩形。温度相关的光致发光（PL）光谱表明，在温度升高至218 K的过程中，带隙PL显著增强，同时与陷阱态相关的PL发生猝灭，这可能是激子-声子耦合的结果。分别通过拟合不同温度下的带隙PL线宽和强度，得出光学声子能量约为50 meV，激子结合能约为120 meV。
