Mode selection and high-quality upconversion lasing from perovskite CsPb<sub>2</sub>Br<sub>5</sub> microplates
Zhengzheng Liu, Chunwei Wang, Zhiping Hu, Juan Du, Jie Yang, Zeyu Zhang, Tongchao Shi, Weimin Liu, Xiaosheng Tang, Yuxin Leng
Abstract
In recent years, halide perovskite nanostructures have had great advances and have opened up a bright future for micro/nanolasers. However, upconversion lasing by two-photon excitation with mode selection and high quality factor in one device is still rarely reported. Herein, two lasing modes are demonstrated in the all-inorganic perovskite <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:msub> <mml:mi>CsPb</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi>Br</mml:mi> <mml:mn>5</mml:mn> </mml:msub> </mml:mrow> </mml:math> microplates with subwavelength thickness and uniform square shape. The net optical gain is quickly established in less than 1 ps and persists more than 30 ps, revealed by ultrafast transient absorption spectroscopy. The temperature-dependent low-threshold amplified spontaneous emission confirms the net gain for stimulated emission with a high characteristic temperature of 403 K, far surpassing the all-inorganic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:msub> <mml:mi>CsPbBr</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:mrow> </mml:math> semiconductor gain media. Remarkably, upconversion lasing based on two kinds of microcavity effects, Fabry–Pérot and whispering-gallery modes, from the microplates at room temperature is successfully achieved with a low threshold operating in multi- or single-mode, respectively. Surprisingly, the quality factor ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m3"> <mml:mrow> <mml:mo form="prefix">∼</mml:mo> <mml:mn>3551</mml:mn> </mml:mrow> </mml:math> ) is among the best values obtained from perovskite micro/nanoplate upconversion lasers without an external cavity. Moreover, the highly stable chromaticity with color drift only less than 0.1 nm also outbalances the all-inorganic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m4"> <mml:mrow> <mml:msub> <mml:mi>CsPbBr</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:mrow> </mml:math> ones. These superior performances of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m5"> <mml:mrow> <mml:msub> <mml:mi>CsPb</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi>Br</mml:mi> <mml:mn>5</mml:mn> </mml:msub> </mml:mrow> </mml:math> microplate lasing with a facile solution synthesis procedure will offer a feasible structure to fabricate specific functionalities for high-performance frequency upconversion micro/nanoscale photonic integrated devices.