A Flat Panel Photodetector Formed by a ZnS Photoconductor and ZnO Nanowire Field Emitters Achieving High Responsivity From Ultraviolet to Visible Light for Indirect-Conversion X-Ray Imaging

Flat panel photodetectors have been well studied for their applications in large area detection such as indirect-conversion X-ray imaging. Even though a few of photodetectors have become commercially available, there is still a room for advancement in responsive wavelength range and sensitivity. This paper reports a sensitive broadband flat panel photodetector that integrates a ZnS photoconductor with an array of ZnO nanowire field emitters. The photodetector exhibits a spectral responsivity of 5.93 × 102–3.79 × 103  A/W with an external quantum efficiency of 1.03 × 105–1.34 × 106% from 350 to 700 nm wavelengths. Additionally, a short signal rise time of 55 ms and a fall time of 1.03 s are demonstrated. The flat panel photodetector with broadband detection and a high responsivity shows a great promise for use in indirect-conversion X-ray detector incorporated with a broad range of X-ray scintillators.

[1]  Safa Kasap,et al.  X-ray sensitivity of photoconductors: application to stabilized a-Se , 2000 .

[2]  Ningsheng Xu,et al.  Novel cold cathode materials and applications , 2005 .

[3]  Yuanlong Liang,et al.  Toward High Uniformity of Photoresponse Broadband Hybrid Organic–Inorganic Photodiode Based on PVP‐Modified Perovskite , 2018 .

[4]  Safa Kasap,et al.  Direct-conversion flat-panel X-ray image detectors , 2002 .

[5]  Sushmee Badhulika,et al.  Fabrication of a solution-processed, highly flexible few layer MoS2 (n)–CuO (p) piezotronic diode on a paper substrate for an active analog frequency modulator and enhanced broadband photodetector , 2017 .

[6]  R. Fowler,et al.  Electron Emission in Intense Electric Fields , 1928 .

[7]  N. Xu,et al.  3-D Dual-Gate Photosensitive Thin-Film Transistor Architectures Based on Amorphous Silicon , 2017, IEEE Transactions on Electron Devices.

[8]  Yong Ding,et al.  Piezo-phototronic Effect Enhanced UV/Visible Photodetector Based on Fully Wide Band Gap Type-II ZnO/ZnS Core/Shell Nanowire Array. , 2015, ACS nano.

[9]  G. Viesti,et al.  Characterization of a Large Area ZnS(Ag) Detector for Gross Alpha and Beta Activity Measurements in Tap Water Plants , 2016, IEEE Transactions on Nuclear Science.

[10]  D. J. Gibbons.  Persistent Internal Polarization of Insulators induced by Electron Bombardment , 1963, Nature.

[11]  Lag Characteristics of Flat Image Sensor Consisting of Field Emitter Array and High-Gain Avalanche Rushing Amorphous Photoconductor Target , 2010 .

[12]  Edward H. Sargent,et al.  Sensitive, Fast, and Stable Perovskite Photodetectors Exploiting Interface Engineering , 2015 .

[13]  N. Xu,et al.  A double-sided radiating flat-panel X-ray source using ZnO nanowire field emitters , 2017 .

[14]  Xudong Xiao,et al.  The epitaxial growth of ZnS nanowire arrays and their applications in UV-light detection , 2012 .

[15]  Kai Wang,et al.  Dual-Gate Photosensitive Thin-Film Transistor-Based Active Pixel Sensor for Indirect-Conversion X-Ray Imaging , 2015, IEEE Transactions on Electron Devices.

[16]  K. Hecht.  Zum Mechanismus des lichtelektrischen Primärstromes in isolierenden Kristallen , 1932 .

[17]  Zheng Lou,et al.  Flexible Broadband Image Sensors with SnS Quantum Dots/Zn2SnO4 Nanowires Hybrid Nanostructures , 2018 .

[18]  L. Luo,et al.  High-Performance Red-Light Photodetector Based on Lead-Free Bismuth Halide Perovskite Film. , 2017, ACS applied materials & interfaces.

[19]  Jun Chen,et al.  Optimizing the Field Emission Properties of ZnO Nanowire Arrays by Precisely Tuning the Population Density and Application in Large-Area Gated Field Emitter Arrays. , 2017, ACS applied materials & interfaces.

[20]  Development of an X-ray HARP–FEA detector system for high-throughput protein crystallography , 2008, Journal of synchrotron radiation.

[21]  Qingfeng Dong,et al.  An Ultraviolet‐to‐NIR Broad Spectral Nanocomposite Photodetector with Gain , 2014 .

[22]  R. Bube,et al.  Laser Saturation of Photoconductivity and Determination of Imperfection Parameters in Sensitive Photoconductors , 1966 .

[23]  N. Xu,et al.  Precisely-controlled fabrication of single ZnO nanoemitter arrays and their possible application in low energy parallel electron beam exposure. , 2012, Nanoscale.

[24]  Norifumi Egami,et al.  Double-Gated, Spindt-Type Field Emitter With Improved Electron Beam Extraction , 2016, IEEE Transactions on Electron Devices.

[25]  Jiangwei Liu,et al.  Flexible Ultraviolet Photodetectors with Broad Photoresponse Based on Branched ZnS‐ZnO Heterostructure Nanofilms , 2014, Advanced materials.

[27]  Lin Wei,et al.  High-Performance Self-powered Photodetectors Based on ZnO/ZnS Core-Shell Nanorod Arrays , 2016, Nanoscale Research Letters.

[28]  F. Julien,et al.  Experimental and theoretical analysis of transport properties of core–shell wire light emitting diodes probed by electron beam induced current microscopy , 2014, Nanotechnology.

[29]  Parikshit Sahatiya,et al.  Large‐Area, Flexible Broadband Photodetector Based on ZnS–MoS2 Hybrid on Paper Substrate , 2017 .

[30]  J A Rowlands,et al.  Design and feasibility of active matrix flat panel detector using avalanche amorphous selenium for protein crystallography. , 2008, Medical physics.

[31]  Maximilian F Reiser,et al.  Advances in digital radiography: physical principles and system overview. , 2007, Radiographics : a review publication of the Radiological Society of North America, Inc.

[32]  Ultrasensitive self-powered large area planar GaN UV-photodetector using reduced graphene oxide electrodes , 2016, 1611.03597.

[33]  Yi Xie,et al.  High‐Performance Flexible Broadband Photodetector Based on Organolead Halide Perovskite , 2014 .

[34]  Hole‐blocking mechanism in high‐gain avalanche rushing amorphous photoconductor (HARP) film , 2011 .

[35]  Sushmee Badhulika,et al.  Strain-modulation-assisted enhanced broadband photodetector based on large-area, flexible, few-layered Gr/MoS2 on cellulose paper , 2017, Nanotechnology.