Electron Tunneling between Si Quantum dots and Tow Dimensional Electron Gas under Optical Excitation at Low Temperatures

We present results of the electron tunneling between Si-dots and the two-dimensional electron gas (2DEG) under the optical excitation at low temperatures, where modification of the 2DEG is caused by optical generation of the electron-hole pairs. We have found that the gate voltage for electron injection to Si-dots becomes remarkably smaller with increase in optical excitation intensity, while the gate voltage for electron emission shows little dependence. The difference in the observed dependences of the gate voltage for electron injection and emission process is explained our proposal which consider the geometrical matching of initial and final state electron wave functions.