We demonstrate spectroscopic measurements on an InGaAs p-n junction using direct tunnel injection of electrons. In contrast to the metal-base transistor design of conventional ballistic electron emission spectroscopy (BEES), the base layer of our device is comprised of a thin, heavily doped p-type region. By tunneling directly into the semiconductor, we observe a significant increase in collector current compared to conventional BEES measurements. This could enable the study of systems and processes that have thus far been difficult to probe with the low-electron collection efficiency of conventional BEES, such as luminescence from single-buried quantum dots.


Likovich, Edward M., Kasey J. Russell, Venkatesh Narayanamurti, Hong Lu, and Arthur C. Gossard. "Direct Injection Tunnel Spectroscopy of a P-N Junction." Applied Physics Letters 95.2 (July 13, 2009): 022106 - 022109.