Size Matters for Energy Conversion Efficiency: Nano Seminar Series

Enhancing thermodynamic efficiency and reducing kinetic losses through size effects can improve energy conversion. I will discuss bandgap tuning for light absorption in solar cells and reducing activation overvoltage as well as ohmic losses
in fuel cells:

(1) I will report on the deposition of Lead sulfide (PbS) thin films by atomic layer deposition (ALD) for the fabrication of quantum well structures. In particular, I will discuss size quantization effects on the bandgap by fabricating PbS quantum wells with a sub‐10 nm thickness. Bandgap values were measured by tunneling spectroscopy (TS) electron energy loss spectroscopy (EELS).

Recent observations on bandgap variations within individual quantum dots will also be described.

(2) To lower the operating temperature of Solid Oxide Fuel Cells, we fabricated corrugated thin‐film electrolyte membranes by nanosphere lithography and atomic layer deposition to reduce the polarization and ohmic losses. The resulting micro‐SOFC electrolyte membranes showed a hexagonal‐pyramid array nanostructure and achieved a power density of 1.34 W/cm2 at 500 C0.

Speaker: Prof. Fritz B. Prinz, Stanford University, MSE & Mechanical Engineering

Room 390