Abstract
We demonstrate a successful selective growth of Si0.3Ge 0.7 quantum dots (QDs) over array of p+-Si nanopillars using a low-pressure chemical vapor deposition technique, and hereafter realized high-performance QD broadband photodiodes for visible to near-infrared photodetection based on heterostructures of indium tin oxide/Si 0.3Ge0.7 QD/Si pillar. Thanks to effective hole confinement and thus a built-in electric field within the SiGe QD, high ratios of photocurrent to dark current of ~2200, 100, and 30, respectively, were measured on our SiGe QDs-based photodiodes under illumination of 9 mW/cm 2 at wavelength of 500-800, 1300, and 1500 nm. The QD photodiode exhibits a very low dark current density of 3.2 × 10-8 A/cm2 and a tunable power-dependent linearity by applied voltage through the competition of electron drift and carrier recombination processes.
Original language | English |
---|---|
Article number | 6544564 |
Pages (from-to) | 1520-1523 |
Number of pages | 4 |
Journal | IEEE Photonics Technology Letters |
Volume | 25 |
Issue number | 15 |
DOIs | |
State | Published - 5 Aug 2013 |
Keywords
- Broadband photodetector
- Selective deposition
- Si nanopillar
- SiGe quantum dot