Black silicon and the quest for intermediate band semiconductors

Presentation Date: 

Thursday, February 6, 2014


Laser-Based Micro and Nano Processing VIII, Photonics West 2014 (San Francisco, CA)

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.