Xiaoyin Xiao, Arthur J. Fischer, George T. Wang, Ping Lu, Daniel D. Koleske, Michael E. Coltrin, Jeremy B. Wright, Sheng Liu, Igal Brener, Ganapathi S. Subramania, and Jeffrey Y. Tsao

Scientific Achievement

We demonstrate the use of quantum-size-controlled photoelectrochemistry (PEC) to fabricate sub-10-nm nanostructures, more specifically, InGaAs quantum dots (QDs).


Historical advances in semiconductor technology have depended on precision fabrication of micro- and nano-structures of ever smaller feature sizes. As nanostructures enter the sub-10-nm size regime, however, precision fabrication becomes increasingly difficult. A combination of nanometer-scale lithography with quantum-size controlled photoelectrochemistry (demonstrated here) might achieve the holy grail of simultaneous control over quantum-scale nanostructure distributions in size and space.

Research Details

  • Our initial set of samples were thin (3-20 nm) epitaxial In0.13Ga0.87N films grown under conditions similar to those used for state-of-the-art InGaN light-emitting diodes
  • Samples were sliced and suspended in a PEC cell for etching via In wire contacts. For the working electrolyte we used H2SO4 which allowed us to completely eliminate etching in the absence of light. For photo-excitation we used a tunable, relatively narrow-band (~ 1 nm linewidth) laser source.
  • QD samples were analyzed using electron microscopies and spectroscopy.