Abstract
The increased use of diagnostic x-rays, especially in the field of medical radiology, has necessitated a significant demand for high resolution, real-time radiation detectors. In this regard, the photoresponse of bismuth sulfide (Bi2S3), an n-type semiconducting metal chalcogenide, to low energy x-rays has been investigated in this study. In recent years, several types of nanomaterials of Bi2S3 have been widely studied for optoelectronic and thermoelectric applications. However, photoresponse of Bi2S3 nanomaterials for dosimetric applications has not yet been reported. The photosensitivity of Bi2S3 with nanoscale “flower-like” structures was characterized under x-ray tube-potentials typically used in mammographic procedures. Both dark current and photocurrent were measured under varying x-ray doses, field sizes, and bias voltages for each of the tube potentials – 20, 23, 26 and 30 kV. Results show that the Bi2S3 nanoflowers instantaneously responded to even minor changes in the dose delivered. The photoresponse was found to be relatively high (few nA) at bias voltage as low as +1 V, and fairly repeatable for both short and long exposures to mammographic x-rays with minimal or no loss in sensitivity. The overall dose-sensitivity of the Bi2S3 nanoflowers was found to be similar to that of a micro-ionization chamber.
Highlights
The increased use of diagnostic x-rays, especially in the field of medical radiology, has necessitated a significant demand for high resolution, real-time radiation detectors
Bi2S3 nanostructures were synthesized through the hydrothermal process using polyethylene glycol (PEG) as a template to obtain flower-like nanostructures
The x-ray field size was determined with a lead cut-out of 1 cm diameter placed on top of 4 mm thick spacers such that the cut-out exposed only the active area of the interdigitated electrodes (IDE) to a 1 cm diameter cone attached to the head of the x-ray tube (Figure 1b)
Summary
The increased use of diagnostic x-rays, especially in the field of medical radiology, has necessitated a significant demand for high resolution, real-time radiation detectors In this regard, the photoresponse of bismuth sulfide (Bi2S3), an n-type semiconducting metal chalcogenide, to low energy x-rays has been investigated in this study. Bi2S3 is an n-type crystalline semiconductor with direct bandgap in the range of 1.3–1.7 eV1–3 Several studies have reported interesting morphologies of Bi2S3 in the form of nanoparticles, nanorods, nanotubes, nanowires, nanoflakes and nanoflowers[1,4,5,6,7,8,9] These 1-D nanostructures of Bi2S3 have been reported to exhibit enhanced electrical, thermal and optoelectronic properties and thereby are extensively investigated for a variety of applications such as photovoltaics, thermoelectrics, infrared spectroscopy, and field emission[8,9]. High sensitivity to low-energy x-rays along with other results suggests that the flower-like nanostructure of Bi2S3 is a potential material for use in semiconductor-based x-ray detection systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
