Highly luminescent and stable lead-free cesium copper halide perovskite powders for UV-pumped phosphor-converted light-emitting diodes
Lingling Xie, Bingkun Chen, Fa Zhang, Ziheng Zhao, Xinxin Wang, Lijie Shi, Yue Liu, Lingling Huang, Ruibin Liu, Bingsuo Zou, Yongtian Wang
Abstract
Lead halide perovskites have drawn extensive attention over recent decades owing to their outstanding photoelectric performances. However, their toxicity and instability are big issues that need to be solved for further commercialization. Herein, we adopt a facile dry ball milling method to synthesize lead-free <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>Cs</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>Cu</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">X</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>5</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:mi mathvariant="normal">X</mml:mi> <mml:mo>=</mml:mo> <mml:mi mathvariant="normal">I</mml:mi> </mml:mrow> </mml:math> , Cl) perovskites with photoluminescence (PL) quantum yield up to 60%. The optical features including broad emission spectrum, large Stokes shift, and long PL lifetime can be attributed to self-trapped exciton recombination. The as-synthesized blue emissive <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m3"> <mml:mrow> <mml:msub> <mml:mi>Cs</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mi>Cu</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi mathvariant="normal">I</mml:mi> <mml:mn>5</mml:mn> </mml:msub> </mml:mrow> </mml:math> and green emissive <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m4"> <mml:mrow> <mml:msub> <mml:mi>Cs</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mi>Cu</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi>Cl</mml:mi> <mml:mn>5</mml:mn> </mml:msub> </mml:mrow> </mml:math> lead-free perovskite powders have good thermal stability and photostability. Furthermore, UV-pumped phosphor-converted light-emitting diodes were obtained by using <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m5"> <mml:mrow> <mml:msub> <mml:mi>Cs</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mi>Cu</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi mathvariant="normal">I</mml:mi> <mml:mn>5</mml:mn> </mml:msub> </mml:mrow> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m6"> <mml:mrow> <mml:msub> <mml:mi>Cs</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mi>Cu</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi>Cl</mml:mi> <mml:mn>5</mml:mn> </mml:msub> </mml:mrow> </mml:math> as phosphors.