A semiconductor heterostructure device that requires no external power source to upconvert two low-energy photons into one higher-energy photon is proposed. This passive device is fabricated in the AlGaAs∕GaAs material system and it is used to demonstrate photon upconversion from 808to710nm at room temperature.

We describe the design and implementation of modifications to an ambient STM with a slip–stick approach mechanism to create a system capable of ballistic electron emission microscopy (BEEM) and spectroscopy (BEES). These modifications require building a custom sample holder which operates as a high gain transimpedance preamplifier. Results of microscopy and spectroscopy using a Au/n-GaAs Schottky device demonstrate the effectiveness of our design.