Abstract
The mechanism of the photoconductive gains of nanowire (NW) photodetectors has not been clearly explained yet, although it is generally thought to be the result of a long excess carrier lifetime due to a large trap density. Here, we demonstrate that the photoconductive gain of a Bi2S3 NW photodetector can be contributed by optical modulation of the electrical injection through contacts. We propose a quantitative model to explain the results based on a model of metal-nanowire contacts. The study shows that optically generated excess carriers can modify the barrier structure at the metal-nanowire interface and thereby increase photoconductivity.
Original language | English |
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Article number | 143110 |
Journal | Applied Physics Letters |
Volume | 99 |
Issue number | 14 |
DOIs | |
State | Published - 3 Oct 2011 |