High-temperature perovskites on Silicon for X-ray energy analysis

Current EDS (Energy Dispersive Spectroscopy) detectors for X-rays are based on the collection of the generated carriers over a large silicon detector volume. The large detector volume is required due to the long absorption length for X-rays in silicon. The accuracy of the obtained energy spectrum is defined by the drift and diffusion of the carrier profile towards the collecting junction and can be affected by the large volume of the detector. In the past years, imec has developed a high-temperature perovskite technology that can be deposited on top of silicon. The much higher absorption of X-rays in perovskites, due to a higher density and larger stopping power of the material, enables a much more compact and much more efficient detector implemented on top of silicon, while a larger band gap can provide a lower limit of detection when compared with silicon detectors. Moreover, imec also has access to the design technology that enables accurate read-out of the carrier profile. The purpose of this PhD is to design, test and measure a new EDS type of detector collecting the X-ray energy spectrum. This will be done by the evaporation of perovskites detector layers on top of the silicon read-out circuit. Eventually, a radiation hard readout circuit will be able to accurately measure the “time-of-diffusion” of the carriers in the Perovskite and derive from these measurements the X-ray-energy spectrum with high accuracy.