NER: Novel Electrochemically Self Assembled Nanowire Infrared Photodetectors

Virginia Commonwealth University, Richmond VA

Investigators

Abstract

This research is focused on demonstrating novel ROOM TEMPERATURE infrared photodetectors based on electrochemically self assembled nanowire arrays. Photodetection is based on photoexcitation of electrons from subband states in the nanowire to trap states in the surrounding insulator. This leads to an "inverse" photodetection effect whereby the conductivity of the photodetector drops when irradiated with infrared radiation. Preliminary experiments [Appl. Phys. Lett., Vol. 79, 4423 (2001)] have shown that these photodetectors can operate at room temperature with a signal to noise ratio of 45 dB. The purpose of the NER project will be to extend this result to create (1) multi-colored detectors using different sized nanowires self assembled on the same wafer, and (2) a complementary photodetector where a normal photodetector is synthesized in series with an inverse photodetector. The complementary photodetector will be able to detect a very narrow band. This research will involve significant work by undergraduate students. The samples that exhibited the novel photodetection effect were prepared by an undergraduate student in the PI's lab.