Near-infrared detectors for photon starved environment

Project leader: Dr. Tihomir Knežević

Project co-leader: Prof. Dr. Lis K. Nanver

Administering organization: University of Zagreb, Faculty of Electrical Engineering and Computing 

Partner institution: University of Twente, Faculty of Electrical Engineering, Mathematics and Computer Science, Integrated Devices and Systems

Amount requested from UKF: 70.512,00 HRK

Amount of matching funding: 67.770,00 HRK

TOTAL VISIT COSTS IN HRK (total UKF funding + total matching funding):  138.282,00 HRK

Project duration: 6 months


Advancing state-of-the-art near-infrared (NIR) photodetectors that will allow more sensitivity, lower noise, higher speeds and high pixel counts and at the same time are compatible with silicon CMOS technology has long been an aspiration of researchers around the globe. All these goals come to together with the further evolution of the single-photon avalanche diodes (SPADs) proposed in this research. The required advancement of the detector technology is uniquely made available by the special properties of pure gallium and pure boron (PureGaB) deposition on Ge islands grown on wafers for CMOS circuit fabrication. In this project, highly sensitive SPADs with nanometer-thin PureGaB layers on Si substrates will be analysed. Electrical and material characterization of PureGaB layers will be performed with emphasis on their temperature dependence which could be utilized to further decrease the dark current values in the photodetector and consequently lower the noise in SPADs such as dark count rate. The findings on the physical characterization will be exploited to obtain the first functional PureGaB model. A simulation study using the PureGaB model will be performed to optimize the electrical performance of the PureGaB SPAD. Purpose of the visit is to connect the expertise on simulation, modeling and electrical characterization of semiconductor devices with new knowledge on cleanroom fabrication and device characterization techniques available at the University of Twente. The development of a predictable and scalable model of Pure(Ga)B-on-Ge, as expected from this visit, will facilitate the design of optimized photodetectors. The knowledge utilized from the visit will be passed to researchers from Croatia which will have the opportunity to develop state-of-the art detectors using a versatile PureB technology. Expertise on PureGaB technology will open new frontiers for research in fields such as two-dimensional semiconductors, quantum computing and advanced semiconductor detectors.