Solution-processed lead-free bulk 0D Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> single crystal for indirect gamma-ray spectroscopy application
Qiang Xu, Juan Wang, Qindong Zhang, Xiao Ouyang, Maheng Ye, Weiting Xie, Xuewen Yan, Deyuan Li, Xiaoping Ouyang, Xiaobing Tang, Xiaodong Zhang
Abstract
Bulk scintillators that are with high density, low cost, and fine pulse-height energy spectral resolution, and are non-hygroscopic and user friendly, are desired for high-energy gamma-ray spectroscopy application. Recently, low-cost solution-processed perovskite nanoscintillators have been demonstrated with outstanding performances for indirect low-energy X-ray detection; however, the stability and thickness are not suitable for high-energy gamma-ray detection. Here, we report scintillation performances of a low-cost solution-processed bulk 0D <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:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>Cu</mml:mi> </mml:mrow> <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> single crystal. The self-trapped exciton emission results in a large Stokes shift (109 nm) that is reabsorption free. A broad X-ray excited emission matches well with the sensitivity of a silicon photodiode. The unique <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mi>Cs</mml:mi> </mml:mrow> <mml:mo>+</mml:mo> </mml:msup> </mml:mrow> </mml:math> surrounded isolated <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m3"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mo stretchy="false">[</mml:mo> <mml:msub> <mml:mrow> <mml:mi>Cu</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi mathvariant="normal">I</mml:mi> <mml:mn>5</mml:mn> </mml:msub> <mml:mo stretchy="false">]</mml:mo> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>−</mml:mo> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> cluster scintillator provides ultra-stability in air and strong radiation hardness under high-dose gamma-ray exposure from a 60 Co source. This solution-processed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m4"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>Cs</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>Cu</mml:mi> </mml:mrow> <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> scintillator is expected with low-cost and has detection performances comparable to commercial alkali-halide scintillator products.