<title>Analysis of the tunnel junction current</title>

In recent years, the development of sub-micron devices has offered the opportunity to transport electric charge by the manipulation of individual electrons. This kind of devices is called single-electron devices (SED), which mainly consist of many tunnel junctions. These tunnel junctions are more like sandwich structure made of metal-insulator-metal or semiconductor-insulator-semiconductor. So to analyze the SED’s characteristics intensively, one must first understand the process of the electron tunneling through the tunnel junction. But some papers make use of the simple approximation in which the tunneling matrix element is often taken as an electron energy-independent constant; some nice characteristics are maybe lost. We concentrate in this paper on investigating the relation between the tunneling matrix element and the energy of the electron. Some important results will be got, the tunnel current will be calculated for typical potential barrier.