MRS Meetings and Events

 

QT03.05.02 2024 MRS Spring Meeting

Developing Bismuth Sulfoiodide Pellets for Low-Energy X-Ray Detection

When and Where

Apr 24, 2024
5:00pm - 7:00pm

Flex Hall C, Level 2, Summit

Presenter

Co-Author(s)

Maia Mombru1,Kavya Reddy Dudipala2,Hugh Lohan2,Robert Hoye2,Matthew Veale3,Laura Fornaro4,Ivana Aguiar1

Universidad de la Republica1,University of Oxford2,Science and Technology Facilities Council3,Universidad de la República4

Abstract

Maia Mombru1,Kavya Reddy Dudipala2,Hugh Lohan2,Robert Hoye2,Matthew Veale3,Laura Fornaro4,Ivana Aguiar1

Universidad de la Republica1,University of Oxford2,Science and Technology Facilities Council3,Universidad de la República4
Bismuth based semiconductor materials are increasing in popularity due to their potential in optoelectronic applications such as solar cells and radiation detection. The latter application has uses spanning many fields, from medicine to homeland safety. Given the nature of soft and hard X-rays and gamma radiation, being able to correctly detect their presence and measure them is imperative. In particular, BiSI has been studied for solar cells, especially in film deposition, and for X-ray detection in pellets from nanostructures. In this work, we present the study of soft X-ray detection in BiSI pellets. BiSI nanorods were synthesized by either a solution or solvothermal method, using mono ethylene glycol as a reaction medium, and Bi<sub>2</sub>S<sub>3</sub> and I<sub>2</sub> as reagents. The solution method yielded pure crystalline BiSI nanorods of 200 nm in average width, while the solvothermal method produced a composite of BiSI nanorods and amorphous carbon particles. Pellets were constructed with the powders by cold pressing in a uniaxial press. The orientation of the BiSI nanorods is parallel to the surface of the pellet, evidenced both by SEM and XRD characterization. In the case of the nanocomposite, this orientation is partly disrupted by the spherical nature of the carbon particles. Prototype devices were built by depositing Au contacts through evaporation in a sandwich configuration.<br/>I-V curves were measured both in the dark and under X-ray irradiation. Dark current was measured up to 600 V and the resistivity was two orders of magnitude higher for the nanocomposite versus the pure compound, with values of 10<sup>9</sup> to 10<sup>11</sup> Ω.cm, respectively. This is in accordance to the fact that the composite has amorphous structure that limits the conductivity. The response to X-rays of 9 keV in energy was measured up to 20 V, and a linear response was obtained in both cases. When the dose was up to 4.2 μGy<sub>air</sub> s<sup>-1</sup> at a fixed voltage of 20 V the current increased linearly. When comparing the two materials, the nanocomposite had a considerable better performance than the pure compound. The amorphous carbon particles lower the dark current, but do not contribute negatively to the photoconduction of the charge carriers generated by the X-rays. A notable advantage of this study is that the bias applied is considerably low with regards to usual operating voltages of direct semiconductor detectors, allowing for the possibility of using these devices in wearable technology, for instance in direct dosimeters. This work presents an easy, scalable and cheap way to produce low energy X-ray detectors with a suitable performance.

Keywords

Bi | optical properties | powder processing

Symposium Organizers

Michal Baranowski, Wroclaw University of Science and Technology
Alexey Chernikov, Technische Universität Dresden
Paulina Plochocka, CNRS
Alexander Urban, LMU Munich

Symposium Support

Bronze
LIGHT CONVERSION
Wroclaw University of Science and Technology

Session Chairs

Alexey Chernikov
Yana Vaynzof

In this Session

QT03.05.01
Controllable Photoluminescence Modification of Monolayer Molybdenum Disulfide via Superacid Treatment and Atomic Layer Deposition of High-κ Dielectric Materials

QT03.05.02
Developing Bismuth Sulfoiodide Pellets for Low-Energy X-Ray Detection

QT03.05.03
Observations and Maps of Second Harmonic Generation on 2D Chalcogenide MoS2 Monolayers and Single Crystalline Thin Films

QT03.05.05
Optical Markers of Magnetic Phase Transition in CrSBr

QT03.05.06
Understanding The Role of Defects in WS2 Layer in Contact with ZnO Substrate

QT03.05.07
Bandgap Opening in Monolayer MoSe2 Induced by Selenium Vacancies

QT03.05.08
White-Light Emission and Diffusion of Self-Trapped Excitons in Antimony- and Bismuth-Based Hybrid Perovskites

QT03.05.09
Tunable White-Light Emission from Self-Trapped Excitons in Ultrathin Sheets of a Low-Dimensional Hybrid Perovskite

QT03.05.10
Elucidating The Impact of Niobium Substitution in WSe2 Nanosheets through Monochromated EELS, 4D-STEM and Deep Neural Networks

QT03.05.11
Star-Shaped WS2 Monolayers with Twin Grain Boundaries Promoted by Molybdenum Atoms

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Publishing Alliance

MRS publishes with Springer Nature