A 4.2 K Very High-Gain/Modulation Factor Silicon Detector/Modulator

An n-well ion-implanted resistor is shown to work as a very-linear high-gain photodetector at 4.2 K. We take advantage of freeze-out and light-assisted carrier ionisation effects to create a photodetector with a current-gain factor G from 1 x 1 0 ~ to 1 . 6 ~ 1 0 ~ . Experimental results show that at the current gain of 1.6x106, excellent linearity in optical response is obtained when the resistor is illuminated with a red-light source.