Advancement in embedding Pb quantum dots into a Porous-Si matrix for superior X-ray radiation detection: An extended gate approach

Abstract

This study reports on the synthesis of porous silicon (PS) and porous silicon doped with lead (PS–Pb) using an electrochemical method with a primary focus on optimizing key synthesis parameters to enhance material properties. During the synthesis, hydrofluoric acid (HF) and ethanol ratios were maintained at 4:1, which was crucial in achieving the desired structural properties. A structural analysis of the synthesized nanocomposites was conducted using Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (FESEM-EDX). This structural analysis validated the successful incorporation of lead (Pb) into the samples. Among the key aspects of this study were the evaluation of the I–V characteristics of the PS-Pb nanocomposites. Based on the findings of I–V measurements, an increase in the bias voltage was observed, which was directly correlated with an increase in measured current, indicating significant changes in electrical properties as a result of Pb doping. Furthermore, the responses of these materials to X-ray pulse irradiation under various conditions were successfully measured and compared, enhancing the understanding of their potential as radiation detectors. The optimal electrochemical conditions for synthesizing PS and Pd-PS were identified as 90 V, 100 mA, 1 s, and 100 V, 100 mA, 0.5 s, respectively. As a result of optimizing electrochemical synthesis parameters, lead-doped porous silicon (Pb-PS) exhibited a marked reduction in pore size, decreasing from an average of 420.88 nm in undoped PS to 244.54 nm in Pb-PS. This structural refinement correlated with improved electrical properties; I–V measurements demonstrated that the current response at a bias voltage of 0.3 V improved from 1.6×10−5 A to 6.23×10−4 An under identical conditions. Furthermore, these materials responded to X-ray radiation and showed enhanced sensitivity, with Pb-PS detectors achieving a lower response time and higher current under X-ray exposure compared to undoped PS. These findings open up new avenues for employing these nanocomposites in advanced applications, particularly in fields that require precise and efficient radiation detection, such as medical imaging and environmental monitoring. This work represents a significant contribution to the field, illustrating the potential of these custom-engineered materials for the advancement of modern healthcare and detection technologies.