The sub-monolayer quantum dot infrared photodetector revisited

• The sub-monolayer quantum dot infrared photodetector (SML-QDIP) is re-examined.
• Original device normal-incidence response was attributed to 3D quantum confinement.
• Modeling shows normal-incidence response is really due to optical cavity scattering.
• Modeling suggests new designs with improved intrinsic normal-incidence absorption.

The sub-monolayer quantum dot infrared photodetector (SML-QDIP) was proposed as an alternative to the standard QDIP based on Stranski–Krastanow (SK) quantum dots. Theoretical modeling indicates that the normal-incidence photo-response observed in the initial SML-QDIP devices, originally attributed to 3D quantum confinement effect, is most likely the result of optical cavity scattering. Modeling results also suggest candidate SML-QDIP structures with improved intrinsic normal incidence absorption.