## 2 Materials and Methods  
In total, 2.615 g of Zinc Nitrate (Zn (NO\({}_{3}\))\({}^{2}\), 6H\({}_{2}\)O) and 1.4 g of hexamethylenetetramine (C\({}_{6}\)H\({}_{12}\)N\({}_{4}\)) were added to 200 mL deionized water to prepare a solution of 50 mM. The solution was then stirred for 1 h at room temperature. 3.31 g of Lead (II) Nitrate Pb (NO\({}_{3}\))\({}^{2}\) salt was added to the solution and stirred continuously. A ZnO seed layer on glass substrates were immersed upside down to the solution, then covered and kept in a chemical bath deposition for 8 h at 90 \({}^{\circ}\)C. The thin film was then removed, washed with deionized water, and dried in air. These steps were repeated three times to increase the thickness of the films. The film thickness was then measured by FESEM, and it was found that the thickness reached 46 \(\upmu\)m. The solution was filtered and dried using an oven at 80 \({}^{\circ}\)C for 15 min, then pressed with a hydraulic press to 1 mm thickness.  
XRD was used to study the structural properties and the particle size for both films was calculated using [PERSON]'s formula, as mentioned in [18]:  
\[\text{d }=\ \frac{0.89\lambda}{Bcos\ \theta\beta} \tag{4}\]  
where \(B\) is the crystalline XRD peak's entire width at half maximum, \(\theta\beta\) is the Bragg's angle, and \(\lambda\) is the X-ray wavelength (0.154 nm). FESEM was also used to study the morphological properties of the samples and then the Energy Dispersive X-ray Spectroscopy (EDX) model was used to determine the fractional weight of each element in a combination. Since the sample is a mixture of elements, effective atomic number (Z\({}_{\text{eff}}\)) of the mixture was obtained using Equation (5) [19]:  
\[\text{Zeff }=\ ^{254}\sqrt[254]{(\text{f1Z}_{1}^{2.94}\ +\ \text{f2Z}_{2}^{2.94}\ +\ \dots\dots\text{fnZ}_{n}^{2.94})} \tag{5}\]  
where, f = the weight fractions for every component in the medium of interest in relation to the total number of electrons consumed within the compound/mixture that forms the medium. Z denotes the atomic number of every element included in the medium. The value used for actual practical applications is generally 2.94 [19]. Silver electrodes were deposited as fingerprint interdigitated on the samples, and silver paste was used to connect the wires. The samples were then connected as an extended gate to the MOSFET to study the I-V characterization under a low absorbed dose (9, 36 and 70 mGy) using the X-ray machine at the School of Physics, USM, and high absorbed dose (1, 5 and 10 Gy) using a radiotherapy machine (Elekta) at Gleneagles Hospital, Penang, Malaysia.  
MOSFET is connected to the semiconductor thick film through the gate to keep the first device away from radiation. Radiation interacts directly with semiconductors, which leads to changes in their properties, such as increase in the amount of current that reaches the MOSFET. The current increases as the amount of radiation dose increases. The EGFET connection setup is mentioned in [18]. The sensing component (ZnO-Pb) and a commercialized MOSFET (CD4007 UB) are the two primary components of an EGFET. Figure 1 depicts the ZnO-Pb-based EGFET X-ray detector. The sensing portion of the sensor was linked to a gate of the MOSFET. The sensing layer was exposed to an X-ray source before being attached to the measuring equipment. The dosimeter's reaction was examined using a Keithley 2400 and Lab Tracer 2 software. The connection used in this work is mentioned in [18].  
The film's sensitivity was measured in terms of the threshold voltage (V\({}_{\text{TH}}\)), which was determined using Equation (1) [20]. The detection sensitivity of the samples to X-ray exposure was determined using the formula below:  
\[S=V_{TH}/D \tag{6}\]  
where \(S\) denotes sensitivity and D indicates the absorbed dose.