Mechanical properties of porous silicon

Abstract

Introducing nanoscale porosity into silicon dramatically lowers its stiffness and hardness in a tunable manner over a wide range. Available data is collated on Young's modulus and Vickers hardness as a function of porosity and layer morphology. There is little quantitative data on fracture toughness and strength, but theoretical work predicts that optimized nanocomposites could be very mechanically durable. The exceptional plasticity recorded for individual silicon nanowires is yet to be demonstrated in mesoporous silicon. A number of application areas are highlighted that rely heavily on the mechanical properties of porous silicon.