"Novel Perovskites for Radiation Dosimetry"

We live in a period where ‘radiations’ just keep increasing exponentially with time. Hospitals (CT scans, X-ray machines), national security departments, research labs, and many more areas play around with radiations and thus are in a high need of radiation dosimeters. Over the years, silicon, amorphous selenium (α-Se), mercury (II) iodide (HgI2 ), cadmium zinc telluride (CdZnTe), high-purity germanium (HPGe), etc. are some of the commercialized dosimeters available in the market. Every existing device in this semiconductor’s era, encourages betterment by overcoming their shortcomings.

Commercial ionizing radiation detectors pose issues like low sensitivity, high leakage current, material instability, low x-ray absorption cross-section, small stopping power, limited spatial resolution, etc. These factors push us towards an exploration of novel materials that overcome these problems. Various borates, phosphates, oxides etc. are being explored over the years. In recent times, a class of materials termed ‘Perovskites’ with a general chemical formula ABX3 , have risen up in exploration for photovoltaic and photo-detection applications due to their many suitable features like tunable bandgap, strong stopping power, large bulk resistivity, radiation hardness etc. Due to the similarity in the principle of photodetectors and radiation detectors, we are extending our research in the exploration of perovskites for radiation dosimetry.

Ideal dosimeters require a high bandgap, high mobility-lifetime product, tissue equivalent Z eff (effective atomic number), high sensitivity etc. We are currently working in the direction of exploring novel hybrid (organic-inorganic) perovskites for dosimetry. A few novel oxide double perovskite structures are being studied now. A DFT (Density Functional Study) based approach is utilized in exploring the properties of these structures. A ‘Machine Learning’ approach will be employed in picking the most suitable hybrid perovskite structures and further in-depth studies on the properties of the chosen materials will be carried out in future.