Novel silicon photomultiplier (SiPM) detector arrays

We are combining recent developments in nanomaterials with the concept of silicon photomultipliers (SiPMs) to develop cost-effective, large-area photodetectors for applications in medical imaging and other low-light sensing applications. Silicon nanowires are grown inside of a template made up of an array of insulating nanotubes on a quartz substrate, generating a close-packed array of vertically-oriented nanowires. A gold layer positioned at the bottom of each nanotube acts as the catalyst for silicon growth. By doping the silicon as it is grown, each nanowire becomes a p-i-n photodiode. A resistive layer provides the necessary quenching resistance for each photodiode, and pixels are defined by ganging the outputs of a region of nanowires together. Preliminary results of the growth process are presented.