Sensitive and Cost‐Effective Detection of Gamma Rays Using Cd‐Functionalized QTF and MEMS–Based Microcantilever Sensors

Ionizing radiation poses a serious health risk to humans; therefore, sensitive detection is significant. Gamma rays are a form of ionizing radiation that can pass through the human body and interact with matter through ionization. Several techniques have been conventionally used to detect ionizing radiation. Despite the advantages of current methods, it is important to develop alternative approaches that can provide cost‐effective, sensitive, and low‐cost radiation detection. Quartz tuning fork (QTF) and microelectromechanical systems (MEMSs) sensors are some of these techniques that have drawn increasing interest. In this work, we aim to detect low doses of gamma radiation with fast response time using a QTF and MEMS sensors coated with cadmium chloride (CdCl 2 ) with different immersion times 2, 8, and 17 h. The structural and optical properties of quartz and silicon‐coated CdCl 2 thin film were also investigated before and after gamma irradiation with different immersion times 2, 8, and 17 h. These properties were analyzed using X‐ray photoelectron spectroscopy (XPS), ultraviolet–visible spectroscopy (UV–VIS), atomic force microscopy (AFM), and spectroscopic ellipsometry (SE). Comparing the resonance frequency shift (RFS) for the three QTFs–coated CdCl 2 , measured using the Quester Q 10 , the RFS of QTF 8 (8 h immersion time) had an excellent response and was about 1800 Hz in the irradiation region. The root mean square (RMS) roughness (Sq) using AFM and the transmittance using UV–VIS of the samples increase after gamma irradiation. On the other side, the MEMSs–coated CdCl 2 results illustrated that the RFS of MEMS 2 (2 h immersion time) was about 4.2 Hz in the irradiation region, measured using the Picomeasure PM3. AFM and SE supported MEMSs results. Both showed a clear increase in the surface roughness of the CdCl 2 as a coating layer onto the silicon substrate after irradiation. Finally, the QTF–based sensor (QTF 8 ) was more sensitive than the MEMS–based sensor (MEMS 2 ) which strongly makes a candidate to be a sensitive detector for low gamma rays.