Femtosecond-Laser Hyperdoping and Texturing of Silicon for Advanced Non-equilibrium Materials

Presentation Date: 

Friday, May 30, 2014

Location: 

2014 AFOSR Ultrashort Pulse Laser-Matter Interactions Program Review (Arlington, VA)

Presentation Slides: 

Shining intense, ultrashort laser pulses on the surface of a crystalline silicon wafer drastically changes the optical, material and electronic properties of the wafer. The process has two effects: it structures the surface and incorporate dopants into the sample to a concentration highly exceeding the equilibrium solubility limit. This femtosecond laser "hyperdoping technique" enables the fabrication of defect- and bandgap engineered semiconductors, and laser texturing further enhances the optical density through excellent light trapping. Hyperdoped silicon opens the door for novel photodectors and for Earth-abundant, semiconductor-based solar energy harvesters with the potential for both low cost and high photoconversion efficiency.