Abstract The issue of organic-inorganic perovskites has received considerable attention because of its importance in improving the efficiency of solar cells. The power conversion efficiency of solar cells has climbed from 3.8% in 2009 to over 25.2% currently. Its outstanding performance is mainly attributed to its long carrier lifetime (101−2 ns), diffusion length (μm), high absorption coefficient, direct bandgap (band gap ~1.55 eV), stable electron/hole migration and other characteristics. In addition to these features, organic-inorganic lead perovskites also have high fluorescence yields and tunable absorption wavelengths, making it an ideal laser gain medium. In this paper, the physical vapor deposition (PVD) is used to grow atomically smooth lead iodide nanoplatelets (PbI2 NPL) on a mica substrate, and convert the PbI2 NPL into atomically smooth single-crystal perovskite nanoplatelets (CH3NH3PbI3 NPL) by chemical vapor deposition. The nanoplatelets can naturally form WGM (whispering-gallery-mode) microcavities. We can control the size of CH3NH3PbI3 NPL (from a few microns to dozens of microns) by adjusting the deposition location, deposition temperature, and deposition time. With the increase of edge length, the mode interval decreases, the peak is red shift, and it shows excellent lasing characteristics with a threshold down to 17 μJ/cm2. This has great application potential in the field of low-cost chip light source.

中文翻译：

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基于气相沉积的单晶钙钛矿纳米片的尺寸控制

摘要 有机-无机钙钛矿问题因其在提高太阳能电池效率方面的重要性而受到广泛关注。太阳能电池的功率转换效率已从2009年的3.8%攀升至目前的25.2%以上。其出色的性能主要归功于其长载流子寿命（101−2 ns）、扩散长度（μm）、高吸收系数、直接带隙（带隙~1.55 eV）、稳定的电子/空穴迁移等特性。除了这些特点，有机-无机铅钙钛矿还具有高荧光产率和可调吸收波长，使其成为理想的激光增益介质。在本文中，物理气相沉积 (PVD) 用于在云母基板上生长原子级光滑的碘化铅纳米片 (PbI2 NPL)，并通过化学气相沉积将 PbI2 NPL 转化为原子级光滑的单晶钙钛矿纳米片 (CH3NH3PbI3 NPL)。纳米血小板可以自然形成 WGM（耳语画廊模式）微腔。我们可以通过调整沉积位置、沉积温度和沉积时间来控制 CH3NH3PbI3 NPL 的尺寸（从几微米到几十微米）。随着边缘长度的增加，模式间隔减小，峰值红移，显示出优异的激光特性，阈值低至17 μJ/cm2。这在低成本芯片光源领域具有很大的应用潜力。我们可以通过调整沉积位置、沉积温度和沉积时间来控制 CH3NH3PbI3 NPL 的尺寸（从几微米到几十微米）。随着边缘长度的增加，模式间隔减小，峰值红移，显示出优异的激光特性，阈值低至17 μJ/cm2。这在低成本芯片光源领域具有很大的应用潜力。我们可以通过调整沉积位置、沉积温度和沉积时间来控制 CH3NH3PbI3 NPL 的尺寸（从几微米到几十微米）。随着边缘长度的增加，模式间隔减小，峰值红移，显示出优异的激光特性，阈值低至17 μJ/cm2。这在低成本芯片光源领域具有很大的应用潜力。