High detectivity photodetectors based on perovskite nanowires with suppressed surface defects
Guohui Li, Rui Gao, Yue Han, Aiping Zhai, Yucheng Liu, Yue Tian, Bining Tian, Yuying Hao, Shengzhong Liu, Yucheng Wu, Yanxia Cui
Abstract
Solution-processable, single-crystalline perovskite nanowires are ideal candidates for developing low-cost photodetectors, but their detectivities are limited due to a high level of unintentional defects. Through the surface-initiated solution-growth method, we fabricated high-quality, single-crystalline, defects-suppressed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:msub> <mml:mi>MAPbI</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:mrow> </mml:math> nanowires, which possess atomically smooth side surfaces with a surface roughness of 0.27 nm, corresponding to a carrier lifetime of 112.9 ns. By forming ohmic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:msub> <mml:mi>MAPbI</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:mo>/</mml:mo> <mml:mi>Au</mml:mi> </mml:mrow> </mml:math> contacts through the dry contact method, high-performance metal–semiconductor–metal photodetectors have been demonstrated with a record large linear dynamic range of 157 dB along with a record high detectivity of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m3"> <mml:mrow> <mml:mn>1.2</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>14</mml:mn> </mml:mrow> </mml:msup> <mml:mtext> </mml:mtext> <mml:mi>Jones</mml:mi> </mml:mrow> </mml:math> at an illumination power density of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m4"> <mml:mrow> <mml:mn>5.5</mml:mn> <mml:mtext> </mml:mtext> <mml:mi>nW</mml:mi> <mml:mo>/</mml:mo> <mml:msup> <mml:mi>cm</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> . Such superior photodetector performance metrics are attributed to, first, the defects-suppressed property of the as-grown <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m5"> <mml:mrow> <mml:msub> <mml:mi>MAPbI</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:mrow> </mml:math> nanowires, which leads to a quite low noise current in the dark, and second, the ohmic contact between <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m6"> <mml:mrow> <mml:msub> <mml:mi>MAPbI</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:mrow> </mml:math> and Au interfaces, which gives rise to an improved responsivity compared with the Schottky contact counterpart. The realized high-performance <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m7"> <mml:mrow> <mml:msub> <mml:mi>MAPbI</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:mrow> </mml:math> nanowire photodetector advances the development of low-cost photodetectors and has potential applications in weak-signal photodetection.