Increased normal incidence photocurrent in quantum dot infrared photodetectors

Jiayi Shao, Purdue University, Birck Nanotechnology Center
Thomas E. Vandervelde, Tufts University
Ajit Barve, University of New Mexico - Main Campus
Andreas Stintz, University of New Mexico - Main Campus
Sanjay Krishna, University of New Mexico - Main Campus

Date of this Version



Applied Physics Letters: Volume 101, Issue 24


Copyright (2012) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters: Volume 101, Issue 24 and may be found at The following article has been submitted to/accepted by Applied Physics Letters. Copyright (2012) Jiayi Shao, Thomas E. Vandervelde, Ajit Barve, Andreas Stintz, and Sanjay Krishna. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


We have increased the ratio of s-polarization (normal incidence) to p-polarization photocurrent to 50% in a quantum dot-in-a-well based infrared photodetector form the typical s-p polarization ratio about 20%. This improvement was achieved by engineering the dot geometry and the quantum confinement via post growth capping materials of the Stranski Krastanov growth mode quantum dots (QDs). The TEM images show that the height to base ratio of shape engineered QDs was increased to 8 nm/12 nm from the control sample's ratio 4 nm/17 nm. The dot geometry correlates with the polarized photocurrent measurements of the detector. (C) 2012 American Institute of Physics. []


Nanoscience and Nanotechnology